The GT40 & GT40P heads had a few differences that are note-worthy, the most importantly being the bump in compression. The Fora platform includes forum software by XenForo. After a couple grand you have a killer set of heads, but there's got to be a less-expensive way of making horsepower. Thanks. Its increase while significant is still only about that of a decent 351 w, hi im building a nastalgic car so im not going to drag race it but it must go ok ive got a 302 windsor basicly recoed stock but i want to run tunnel rams to go with the the3am would like to put choppy cam and replace the heads any ideas would be much apprecited thankyou, What is the stock head cc of a 1992 f150 302 windsor. Because of this, your tuneup will probably need to be modified. this head fits years 95-01 explorer mountaineer mercury mountaineer . When you purchase through links on our site, we may earn an affiliate commission, which supports our community. Location: Re: Stock Ford 351W 4bbl dyno numbers. Using the manufacturer recommended springs for your camshaft are a safe bet. Best of all, no machining is required to install these on your stock cast iron heads! at the crank. That's more than enough to feed a power-brake booster. They were located in Tahachapi CA, and were sold with upgraded springs for $650.00, back in 2002-2003 ish. We also added a veteran Ford magnetic pickup distributor and used it to drive an MSD ignition system. Not sure about that but got some pictures of the cast iron explorer manifolds on a 302. You will have to get special headers to fit these heads since the spark plugs are angled differently than normal 5.0 heads. Not bad for off the shelf parts and a stock shortblock. Dennis Hilliard of Central Coast says we can expect to gain three-tenths in the quarter-mile. Its funny no one mentioned anything about ignition timing or components, Your email address will not be published. The factory heads have a boss for the exhaust valve that restricts flow through the exhaust port. GT40, GT40P, would be great factory heads. .. i would not buy valves unless you need them amd would not switch to studs with these heads for your low hp . Im a different animal. The Edelbrock Performer RPM is a good choice, but Holley, Weiand and Ford Motorsport also have similar offerings. Over $2050 for the 165/185 renegades. +1 I would go with the regular GT40 heads. The HP DIFF column on the far right lists the horsepower difference between Test 1 and Test 3. '85 GT vert two tone (white on charcoal)white leather, http://www.facebook.com/groups/233213650060739/, http://www.summitracing.com/parts/TFS-2500100/, ascMcLaren & Motorsport/Grand Prix IV Capris, RHD and Other International/Export Models, Mods, Maintenance & Mechanical FAQs/Archive, If this is your first visit, be sure to
There are caveats to this plan, however. The kit offers adjustable power from 50 to 250 hp with a simple jet change. Generally expect with a good cam, intake, roller rockers and a good ignition system to see around 300-350 max rear wheel horsepower, depending on what type of dyno you use. I need that part number too! T5z and 3.89 9" TL rear. That's a 40 per cent increase in power from a simple head and cam swap, and one seriously happy Mustang owner! LOW-BUCK 302 FORD HEAD UPGRADE Richard Holdener 239K subscribers 189K views 2 years ago WESTECH PERFORMANCE GROUP WHAT'S IT WORTH? Ford GT40P 302 5.0L 4 Bar Cylinder Head Assembly Pair w/ 1/2" Head Bolt Hole. Assorted screwdrivers, pliers and vise-grips. ***Most important is theStupid question is the one that was never asked!*** I got lucky and found a complete Explorer GT40P engine online. Through Central Coast you can have the heads fully prepped for your combination. Test 2: Changed to the smaller of the two Lunati camshaftsno other changes. I got a set of AFR heads , night and day. Im running stock GT40 heads with stock 4.000 bore on cylinders and a Lunati cam with 256/262; Duration @ .050 (Int/Exh): 213/219; Gross Valve Lift (Int/Exh): .483/.499; LSA/ICL: 112/108. Perhaps even more surprising was how well this engine idled, calmly purring with 16 inches of manifold vacuum at 980 rpm. REMANUFACTURED FORD 302 5.0 COBRA GT40 CYLINDER HEADS. In mid-1997, the Explorer and Mountaineer 5.0 L heads were revised and renamed . Add a distributor designed for a carbureted 302 but make sure to install the correct distributor gear for your cam. Yeah, out of a bolt on upgrade, you'd probably be looking at 260-280rwhp ish with supporting mods. 69.90.139.244 I recall having an absolute blast with my old K-code coupe back in the day. I'm an old school guy (289 in 65 mustang), and I'm just looking into the new 5.0 engine (roller cam) stuff recently. For a better experience, please enable JavaScript in your browser before proceeding. Ford GT40P 302 5.0L 4 Bar Cylinder Head Assembly Pair w/ 1/2" Head Bolt Hole. They work, but present their own challenges. As you might expect with more duration, the idle quality dropped significantly but was still able to make 11.5 inches of vacuum at 980 rpm. JavaScript is disabled. I bought a crate 302 from Downs Ford a few years ago that was producing 320 hp. A solid 300-325 hp should be plenty and that's with good drivability and reliability as well. I guess I had it backwards, sorry about that, didn't mean to spread misinformation. Ported Hurricane Single Plane and custom 750 HP. Nice to see actual dyno results instead of "butt dyno" guesses. There are several actions that could trigger this block including submitting a certain word or phrase, a SQL command or malformed data. Test 3: Installed the larger Lunati camagain, no other changes. Just got through porting one of my gt40p heads today. Sponsored. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. E303 Cam advanced 4 degrees. A forum community dedicated to Ford performance owners and enthusiasts. The MPH was there to run a little better but the local track is about terrible. SB Ford GT40P Drop In Valve Springs Kit, Hyd Roller w/ Stock Cam, .450" lift and below. I was thinking the same but the enforcers are $647ea now so $1400 (inc tax) is the entry price for good set of heads. I ran the Speed Pro L2488 pistons and it had me around 9.9 compression with a .041 head gasket, Now I had GT40 heads milled .020 and so that's just a guess on the CC. Your email address will not be published. The only failures Ive had were timing chains and a couple broken rods in a mid 80s 302 with 200,000 miles on it that got about 35 lbs of boost stuffed into it when a pop off valve I bought on ebay failed. If this is beyond your technical ability, you could ask a local machine shop to perform the modifications. Because its all been done time after time after. 87-93-95 Ford Mustang GT40P Engine Cylinder Heads REBUILT 302 351 GT40 SBF OEM | eBay Motors, Parts & Accessories, Car & Truck Parts & Accessories | eBay! You need to check. If I remember right, non of the GT40P's (later models) had the thermactor smog provisions. Shop by category. For all of us interested in Gt40p heads. GT40s have 64cc chambers. Some ideas never go out of style. Have fun, be safe, enjoy. Scorpion 1.6 roller rockers. I'm also have the regular GT40 heads on my current build. Its always refreshing to see a FORD getting a little face time in your column, even if its a tired 302 with no great expectations of setting the world on fire when the dust settles. (its not their engine) Going from your heads to the GT40p heads will bump your compression by about a point.so hello bottom end torque. Jeff Smith has had a passion for cars since he began working at his grandfather's gas station at the age 10. We know what you're thinking--only two-tenths from an extra 45 hp? Maybe I'll think about a cam swap? They suffered from poor aftermarket support up until about 15 years ago when it really came on strong. 950.00 us a set and will ship . This is a common mistake with first-time cam buyers who dont necessarily appreciate that the cam is just one component of the overall engine package. With. Be careful, I was once bitten by one of those reptile engine builders. Come join the discussion about performance, builds, modifications, reviews, engine swaps, classifieds, troubleshooting, maintenance, and more! You can email the site owner to let them know you were blocked. Theres many options available for a little more power. Can I run the new cam with the same roller hydraulic lifters or do I have to change the lifters too? When you purchase through links on our site, we may earn an affiliate commission, which supports our community. Keep in mind that swapping camshafts is a fairly extensive effort. 97% Positive Feedback . JavaScript is disabled. The tube headers showed a gain of almost 100 hp! I have a 432 HP non Hi Po 289 I built. Free shipping for many products! Boy, were we surprised with the results. Cast iron GT40Ps as cast flow better than non-Ps due to revised plug location/angle. While we've seen engine dyno tests performed with GT-40P heads replacing factory E7TE castings and resulting in a boost of more than 25 hp, we have reluctantly set our horsepower gain goal at 25 ponies, as well. The reason this new generation of Ford engines make a ton more power is they also enjoy fantastic cylinder heads and four valves per cylinder. How to Build a Budget 383 Stroker Chevy How do I Increase Horsepower on a 440 Cylinder Head Specifications for a 1969 How to Get More Power Out of a 92 4.3 dragster engine image by Robert Young from, Copyright 2023 Leaf Group Ltd. / Leaf Group Media. The action you just performed triggered the security solution. Ford Factory 5.0 Performance Cylinder Heads. just curious. Their weak point is that the rotator used on the exhaust valve is very thick. Motor is going into a Ranger. The valve seats have been cut on a . Cant wait to try um out. I went to a couple in Tucson and almost all the Ford vehicles that came with a 5.0 had the heads missing. *** 65 Mustang 351C 4v, AOD, 4.11 gears *** 66 Galaxie convert big block. Actually the regular gt40's in either aluminum or iron are the good ones but the gt40p's are only a slight improvement over regular 302 heads. P-heads have a smaller combustion chamber at 59cc, which will bump the compression ratio up on an otherwise-stock 5.0 engine. Mac and Ford Motorsport both make a GT40P spacific header. But don't think that adding a bigger camshaft will make more power. Install a set of GT-40P cylinder heads from a late 1990's Ford Explorer or a set of GT40 heads from an early 1990's Mustang 5.0L. check out the. Learn how your comment data is processed. Well that article just got me very ancy, I want these heads!! BONUS TEST-FOUR DIFFERENT 302 INTAKES.. But what we were most impressed with was the solid gain in torque over the smaller Voodoo cam from 3,500 and up. The newer camshaft is designed for use with a soft bronze distributor gear, not the hardened steel gear used for older camshafts. With nitrous, this is easily a mid-11-second ride. Not when you can buy a set of Promaxx or AFR Enforcer heads for $1000, that already have decent hardware included. So I've got the motor and heads already for my maverick project. I've got gt40p heads for it I'll be running, and can't afford better . You might even say its like flogging a dead horse without any animals actually being injured during my moments of sarcasm. well i finally did my first ever carb build, ive always been an EFI guy Black 1985 GT: 408w, in the 6's in the 1/8 mile. Vehicle: 1972 2 door 302 maverick, 1986 5.0 stang gt convertible,66 mustang coupe, HEMI ram. You keep stock drivability, and stock gas milage if you can stay out of boost. Assuming this will be a daily driver engine, a short duration camshaft, especially when combined with a four-barrel dual plane intake manifold and headers, will deliver extremely snappy throttle response and the whole combination will increase the torque and peak horsepower by somewhere in the neighborhood of 20 to perhaps 35 horsepower. Once you get into the FoMoCo aftermarket aluminum GT40s though, all bets are off. I have a 66 mustang with its original untouched 289 with over 140 k on it that Ive been running a blow thru turbo making 14 lbs of boost on for the last 5 years and its never given me a problem. It's an 86 roller 5.0 engine that had a recent rebuild sometime in the past with keith black pistons, otherwise stock. Sponsored. We also discovered some issues with the GT40P heads that required changes, so we added valves from Manley that eliminated the exhaust-valve rotators and allowed us to set the proper valvespring installed height. Tim's junkyard refugee survived the beating and we had a bitchin' story. You can have your current 28 oz rebalanced to 50. Horse Sense: The smaller valves found in GT-40P heads improve airflow velocity. Every thing he tells you on this site is true. At the time, I was still running smog equipment in a 1994 Mustang GT, so I had them drill the back of the heads for the thermactor connection. What would be the best cam and springs to use for these heads in a 302 Windsor? This is needed for the steel roller cam. Also, you'll need to get a steel distributor gear to replace the iron gear that is currently on your distributor. the springs are new stock oem ford. Limited header choice is certainly a challenge. Please include what you were doing when this page came up and the Cloudflare Ray ID found at the bottom of this page. I am very happy too. A forum community dedicated to Ford Mustang owners and enthusiasts. This is what I recommend to everyone who is doing a budget 5.0 build. 1986 Short block with notched pistons. Small Block Ford 289/302/5.0L/351w 180cc/60cc Aluminum Cylinder Head E42004. I spin it to 6500 and thats about it. I can tell you that with my 9.503 block, 22cc dished pistons and 64cc heads, I'm at 9.5:1 compression. For 2018, the Coyote makes 460 hp. However, theres a distinct possibility that I might pull all of my hair out if I see another in-depth article explaining how I, along with just over a billion other desperate humans seeking answers, need special valve spring split locks for my next tired Chevy build. A forum community dedicated to vintage Ford Mustang owners and enthusiasts. You will have to address the 50 oz balance of the 5.0 engine by getting a 50 oz flywheel. It took him and yours truly eight hours from start to finish, using air tools and a lift to gain access to the header flanges. We started with a 120,000-mile 5.0L out of a Ford Explorer, removed the EFI and DIS, and pocket ported the stock GT40P iron heads with stock valve sizes. T5 with 3.73s. Then why did you port the heads and how do you know if you made an improvement. This one added another 10 degrees of duration over the smaller Voodoo cam, along with 0.020 inch more intake valve lift. 68 Mustang GT/CS Highland Green, PS, PB & Console, C Code w/C4 & 3.55 8 rear, If you aren't using the GT40P's stock, with maybe a spring upgrade and valve job, they aren't worth it anymore. The heads got a 3 angle valve job, new valves from speed-pro and all the valve train was from crane that matched the current hydraulic cam. That's a good combo in my book. Don't let the fact that the iron GT40 heads have a larger exhaust valve fool you. We probably could have coaxed an even 300 hp out of this stock configuration, but with such good numbers, we decided to jump right into the first Lunati cam. No-option stripper- I like strippers. Purchase a set of flat top pistons (from Ford Motorsport, TRW or Keith Black) with machined valve reliefs and designed to provide 10:1 compression with a 59 to 60 cc combustion chamber cylinder head. Choose a cylinder head before you install the pistons. Torque on the other hand isnt something to write home about. If they are cheap enough, take them anyway. 1 - 7 of 7 Posts. Along with the heads, we used MAC headers for GT-40P heads. I'm running BBK un-equal length shorty's, and I'm able to get all the plugs in, tight, and all plug wires on. This website is using a security service to protect itself from online attacks. Common sense would suggest that with the heavy lifting complete and the old cam removed, by not installing the new roller lifters along with the camshaft could be asking for the possibility of trouble just a few thousand miles down the road. 68 XR7 & 68 M-100. They fill that spot between power and budget. United Engine and Machine sells cheap but decent pistons that will do what you're wanting. I'm running stock GT40 heads with stock 4.000 bore on cylinders and a Lunati cam with 256/262; Duration @ .050 (Int/Exh): 213/219; Gross Valve Lift (Int/Exh): .483/.499; LSA/ICL: 112/108. Start with any 302 block, but try to find one from 1985 and up since it will already have provisions for a roller camshaft. We are offering a pair of original Ford Cobra 5.0 GT40 cast iron cylinder heads. You didnt mention which cam you had in mind. Ive bought wrecking yard SBFs and put 20 lbs of boost to them and spin them to 7000 and made 500 HP with several of them. The engine never huffed oil out of the breathers, and the spark plugs all looked excellent. JavaScript is disabled. When building an engine there is a lot to take into consideration. Everything fits, use the stock rockers and pushrods. After graduating from Iowa State University with a journalism degree in 1978, he combined his two passions: cars and writing. I guess someone could just do a basic valve job and throw on the GT40 upper/lower intake for a cheap HP boost. With gt40p heads and 289 hipo exhaust manifolds changing sparkplugs is the same as the original 302 heads and manifolds, I use the spark plugs that are recomended for the explorer with gt40p heads and you can use straight or angled boots. 68stang351 Founding Member May 16, 2002 850 If you're running a stock cam, 1.7 rockers will work perfectly. Car Craft mag. At 4,300 rpm, the torque peaked at 348 lb-ft, a solid 20-lb-ft improvement, and the Lunati continued to outperform the stock cam all the way through with a peak horsepower increase of 60 hp at 354 hp at 5,700 rpm! While the heads were off getting a massage, we turned our attention to the cam timing. When you purchase through links on our site, we may earn an affiliate commission, which supports our community. P-heads have a smaller combustion chamber at 59cc, which will bump the compression ratio up on an otherwise-stock 5.0 engine. Posted on May 07, 2014 by promarengine. Commonly referred to as Explorer heads, GT-40P iron castings are found on current 5.0-equipped Explorers. Early Windsors tend to have fairly restrictive exhaust manifolds, making the addition of a set of headers that much more efficient. The reason for this is that we're actually replacing mildly worked E7TE heads. This will follow the guideline of a 1.6 rocker baseline and factory bottom end 79-95 related 5.0L Mustangs only. This is not a criticism but instead consider it to be more of a heads-up. I got rid of the carburetor and went with a F.A.S.T. Yes- thank you. All manufactured using advanced CNC technology for the extreme durability and precision required of the modern canted valve Ford Small Block at power levels around the 1000 mark reached during recent competitions at the EMC and at the strip. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); This site uses Akismet to reduce spam. 1983 Mustang G.T. These are some of the best castings Ford ever produced for this engine, and are still fairly cheap and available used. Manual trans. this is the price for one head. In less than an hour, we were ready to test. I view the GT40P heads similar to Granada brakes. Richard Rowe has been writing professionally since 2007, specializing in automotive topics. But the part about a cam replacement possibly being a labor intensive undertaking is correct. Stock 1989 5.0L HO pistons will work if you can find them. We took the heads to Mike Slover of Slover's Porting Service in Sun Valley, California, to do this work, plus some basic pocket-porting to improve flowespecially on the exhaust side. Not looking for crazy HP. I love my setup and it is very strong engine. I have been working on Fords for 40 years and I have experimented with a few tricks of my own. I would like to know what heads, cam and intake manifold combination to use for the most HP I can squeeze out of that motor. It's a classic move we've pulled off many times. You didnt mention what camshaft you would be choosing or exactly which 5.0L Ford Windsor engine you are working with. Test 1: 750-cfm carburetor, dual-plane intake manifold, and stock camshaft. Keywords I've not seen a set of longtubes that have an issue with GT40P's, either. Hey all, I'm working on building a 302 with my gt40p heads. that is a healthy budget deal. However there are plenty of factory heads that with the help of an experienced machine shop can be great. Good on ya Jeff Smith. Yank a motor out of the junkyard, clean it up, add a camshaft, intake, and a carburetor, and see how much power we can squeeze out of it. I'll save the effort and lighten my front end by 50# with aluminum. I have heard this rod bolt weakness myth for years but have yet to have a single problem with them in any of the SBF engines I have pounded on for the last 30 years and there have been lots of them. Yes Mr.Smith, your column here at OAC adorned with extreme performance without power adders, or all Engine as its known, from a superior pushrod Small Block featuring almost all USA sourced modern components with the familiar smell of Ford Blue. With the P-heads requiring pedestal-mount rockers, we also called up Crane Cams for a set of 1.6 pedestal-mount roller rockers. Yea. I have a 5.0 from a 1992 Mustang in my 65. Yea. You didnt provide a lot of information about the engine itself, Im assuming its 85 or newer ( roller cam) May need a freshen up of the bottom end if compression is the issue. - I have a 1989 f150 with a 302 5 spd. $700.98. These are some of the best castings Ford ever produced for this engine, and are still fairly cheap and available used. Even with relatively small valve sizes of 1.85-inch intake and 1.46-inch exhaust, the P-heads flow much better than previous. Long tube headers are a terrific idea, but you need to open up the exhaust side. The dyno recorded a peak horsepower reading of 489 hp, but the air/fuel ratio was slightly on the rich side at 11.5:1, so we increased the nitrous jet to a 61 and hit the button again. i know a guy who used to build race engines so he has all the right tools, how much would it help to get the heads ported and polished or anything else he could do to them. This engine will be good for your 65 Mustang. Ill do springs and a moderate cam and go for a good, dependable power plant. There are a couple of reasons for this suggestion. So . Assemble the rotating assembly with a stock 5.0L crankshaft, a set of 5.0L rods and the specified pistons with stock-type rings. Different years can have different combustion chamber sizes but ffor the most part there will be no performance increases by going with 302 heads. There are a lot of variables that must be addressed to give a better estimate, but a good basic estimate is 20-40 HP at the crank. I have a 302 Windsor V8 EFI engine that I converted to a 600 cfm carburetor with a Street Warrior intake manifold. With the tuning finalized, the little cam made far more power than we expected, cranking out 328 lb-ft of torque at 4,200 and 294 hp at 5,400 rpm. 402 HP NA from a HI PO 289 isnt that mysterious of a feat to accomplish with todays SBF Aftermarket parts availability. . http://vb.foureyedpride.com/showthread.php?t=89153, http://www.facebook.com/groups/233213650060739/, ascMcLaren & Motorsport/Grand Prix IV Capris, RHD and Other International/Export Models, Mods, Maintenance & Mechanical FAQs/Archive, If this is your first visit, be sure to
This will cost additional money but is still worth it, in our opinion. This is a function of the somewhat wider lobe-separation angle of 112 degrees. Thank You. In an effort to preserve the history of the Early Fox Era, FEP covers the following vehicles: 79-86 Mustang and Capri, 84-86 Mustang SVO, 78-83 Fairmont & Zephyr, 83-86 LTD & Marquis, 80-88 Thunderbird & Cougar, 82-87 Continental, 84-92 Mark VII, 81-82 Granada. Slover primarily focused on the exhaust side of the GT40P heads. Come join the discussion about performance, production numbers, VIN decoders, modifications, troubleshooting, power adders, DIY tutorials, and more! Come join the discussion about restoration, modifications, NOS parts, troubleshooting, VIN codes, and more! . 302 .030 over with; Scat Forged Steel Rods, SpeedPro pistons and rings . I turned it because it was tired when I got it. He'd be the best source. We will go into more detail on the head mods in a later story in Junkyard Builder, so watch for it. AFR 165cc 58cc Heads. I got a GT40P off the assembly line years ago. Obviously, tuneups will vary. If you smooth out the bowls and exhaust ports and gasket match the intakes they should flow decent. I am working on a set of iron GT40s hoping it goes faster. VerticalScope Inc., 111 Peter Street, Suite 600, Toronto, Ontario, M5V 2H1, Canada. Features hardened 4140 Chromoly retainers, valve locks, spring shims, a spring height gauge, valve seals, and instructions. When compared to the new generation of performance engines on the market today like the 5.0L DOHC Coyote engine, your engine will not come close. The multiple-layer steel construction allows the gasket to conform to movement between the cylinder head and block while maintaining a good seal. Instructions on porting the GT-40p heads here. You gave me the info I was looking for, and I really do appreciate it. Many years ago, a friend bought a used 2001 Mercury Mountaineer 5.0L that was equipped with a set of really decent GT40P style iron heads. Do you guys have part numbers for the spring kits? There is a better way. Compare. Actually, making around 240 to 250 hp with a near-stock Windsor 302 will feel pretty good. Even with a stock Mustang 5.0 cam makes good power. Not *as* good as the GT40p heads, but I'd prefer to not have to worry about exhaust fitment issues, or have a narrow range of what I can work with. Dec 8, 2011. JUNKYARD GT40P HEADS-ADD 30+ HP TO YOUR 5.0L (FOR FREE?) It runs smooth but seems lazy. The car weighs #2835 with driver. how hard to put on? This combination should be good for about 400 horsepower and as much as 500 if you opt to use the stronger aftermarket pistons. check out the. PTP Engineering front suspension and 25540R17s all around. With the GT-40P heads you will need to back off the timing a couple degrees and bump up the fuel pressure. The only way to really make more power is to go with a stroker kit, blower and/or heads. The engine was only rated at 215 hp, but it at least had 9.0:1 compression. They are more expensive than standard head gaskets, but they also do the job and are worth the additional money. Like I said lots of options. If you know him, ask him. Calculated compression to 9.8:1. We decided to test both ideas, so we ordered two roller cams from Lunati: a shorter-duration cam that would deliver decent idle vacuum and maybe make around 320 to 335 hp, and a longer-duration version that might push the horsepower up to perhaps 350 hp. If you can get the mentioned GT-40 heads with studs for a good price, that would be good for you. GT40p heads peak horsepower was [email protected] with 363ft/[email protected] The worked 351 heads showed peak . FULL DYNO RESULTS. All costing in the end at least another $2k. Note the head bolt hole issue, some GT40 iron heads had 1/2 holes, if not they will need to be enlarged. Took me 7 hours to do one head.but they cleaned up real nice. Central Coast Mustang sells GT-40P heads at a great price, making them a viable alternative in a market flooded with performance head choices. Stock valve sizes? I added a link to it. In a 3,250-pound car like a Mustang with 3.50 gears and an automatic with a 2,800-rpm converter, this 5.0L could pull 12.80s at 108 mph. Small Block V8 (221, 260, 289, 5.0/302, 5.8/351W) - GT40P heads? Ive been building ENGINES for 40+ years. There's not a lot of reson to use 351 heads later than '75 since they essentially identical to 302 heads except for head bolt holes. I just read about this build on the corral.net. The older pushrod engines just dont offer the same kind of power potential for their displacement and it all has to do with cylinder head flow. In addition, the cam timing was designed for torque, with duration somewhere around 190 degrees at 0.050 with roughly 0.450-inch lift. MAC is the only manufacturer of these headers, and the parts we installed fit like a glove with no problems whatsoever. All this is worth it. I'd get the gt40 setup, and put an s trim on it. ported GT-40p, ported cobra intake, 65mm BBK, e-cam with 1.7s, longtubes, off-road x-pipe with flowmasters dumped. Again, assuming this is a nearly stock 5.0L with stock heads, the Weiand Street Warrior dual plane intake and 600 cfm carburetor, its important to not become overly aggressive and choose a big camshaft. Part of this reason is due to its inherent strength and simplicity, but a lot of it has to do with how little Ford has changed it over the years. You can use the stock roller lifters with any size cam you want. Compare. many thanks to all you eco-hippies giving me dirty looks and helping me feel llike an overall badass rebel. And agree the cams do help and a few tricks with the heads that I have discovered really make a difference. SBF engines are modified constantly. When combined with modern power-makers, such as nitrous, the 302 is more than capable of producing 400+ horsepower for little more than the cost of a stock engine rebuild. Not to mention, they will run circles around GT40P's out of the box. THANKS VERY MUCH! 69-70 302 heads (the ones with the heart-shaped combustion chamber) Any early 289 heads for the chamber size (but you'll have small ports & valves w/all that CR) Flat Ernie, Aug 27, 2011 SHARE POST #8 fordfan289 Member from indiana correct me if Im wrong but cant you use 351c heads and get the same thing as a 302 boss.