I found these on e-Bay. http://cgi.ebay.com/ebaymotors/ws/e...ry=33617&item=7943347489&rd=1&ssPageName=WD1V What is so good about GT40 heads? E7TE? I hear that a good number of you guys have them. How do they compare to new Edelbrock or Darts, or similar? Also, what should I look for in heads? What can I get from a junkyard, in stock condition, that would be good for current improvements and later fixed up for even more improvement? Especially something we can find cheap. I am very uneducated about heads, and it sounds like I am not alone on this site, so any information would be appreciated by many.
http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=129017&prmenbr=361 http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=168620&prmenbr=361 What about these? Can we "bolt on" if it says "hydraulic roller" and we are not using a roller cam?
Good Questions! The GT40 heads you found on eBay are an aluminum version of Ford's cast iron GT40 used on later 5.0 Mustang GTs, Cobras, Lightening trucks, etc. The iron GT40s replaced the E7TEs irons. There was nothing special about the E7TEs but they flow slightly better than the heads that came on our cars. The heads used on 70s small blocks were actually originally designed in the early 60s for a 221 cid motor! Some changes in chamber, port and valve size were made when engines went from 221 to 260 to 289 to 302 cid. But in general the chamber designs were not very efficient and the ports were terrible, not only in size but shape. Ford's only concern at the time was making a compact head for a narrow V8 that would fit between the shock towers of Fairlanes, Falcons, Mustangs, Comets, etc. It was the exhaust port that got the short end of the stick as far as efficiency. Even the 289 HiPo head was pretty crappy. It's only improvments over the standard 289 head was that it had stiffer valve springs w/machined pockets and threaded rocker studs for the solid lifter cam that came in the 289 HiPo. Sometime compare early Ford small block heads to Chevy heads from the same period. Port and valve sizes on the Chevys were usually larger and the heads were wider to promote better port shapes. That's why Chevy engines dominated for so many decades, better heads. The Chevy engine designs didn't have to fit between shock towers like Ford products. The 351W head was the same basic design as the 302 but with a more open, larger chamber, bigger valves and ports. That's what Ford should have using on 302s all along. The 351W was an improvement but still had poor flowing exhaust ports and lower compression because of the larger chamber. With almost any Ford factory head you should run a dual pattern cam that provides higher lift and more duration to the exhaust valve to help compensate for the poor flowing exhaust port. For the same reason any opening up of the exhaust port will make a big difference. The 5.0 E7TEs were a step up from the old 302 heads. The iron GT40s were a step up from the E7TEs. The aluminum Gt40s are a step up from the irons. Somewhere between the iron and the aluminum GT40s is the GT40Ps, which is what I run on my engine. In the same range as the GT40Ps you have aftermarket iron heads like Rousch, World Products, Dart. The Edelbrock aluminum heads are very similar to the aluminum Gt40s. The AFRs and Dart Pro 1s work better yet but you'll pay about $350 more for a pair. The Kaase heads are very expensive, basically a Cleavland design for Windsor engines, kind of like an updated Boss head with canted valves. They need special pushrods, valve covers. Only use these for an all out race engine. You can spend a lot of time and money on reworking iron heads and get them to flow very well, but not as wel as aftermarket aluminum pieces. Your intended usage should determine what heads you choose. For an everyday street car or cruiser slightly reworked iron heads are fine. If you need eye candy or are gonna race, aluminum heads MAY make more sense. It's all about knowing what you want/need then matching everything in the engine to reach that goal. Aluminum heads are not as thermally efficient (don't hold as much heat in the combustion chamber) as iron heads so you need about a full point more compression to use them. Nowadays, depending on what kind of pump gas they have in your area of the country, iron heads can get away with a compresson ratio of around 9 - 9.5:1. Aluminum heads 10 - 10.5:1. Whichever heads you choose you have to match compression ratio, carb and intake, cam, and exhaust parts. It's a package deal that takes some planning up front. Usually the valve springs for a stock hydraulic roller cam will be ok with a flat tappet cam. Talk to the head/spring manufacturer to know for sure. I called Ford Racing tech about the same issue when I was installing my P heads. In my case my car is a cruiser not a bruiser. 347 w/ P heads, 9.2:1 compression, 600 cfm Holley on an Edelbrock Performer intake and cam, 1 5/8 long tube headers. Yeah I could make more power with a bigger carb/intake/cam/heads but considering the way I drive the car 99% of the time my combo works fine. Desktop Dyno guesstimates I have about 325 hp but 387 lb ft of torque at only 3500 rpm! Just what you want for a street driven car. For the "other" 1% of driving, certain "passing" situations, I also have a 125 hp shot of nitrous.
If I go to the junk yard and find some mustangs (or other fords with those heads), what year models will have the GT40s, and how do I identify the heads? What other vehicles will have them?
Nice job BMC. I've seen the list of what came on what but can't find it now. It's out there somewhere.
I have done some searching, and cannot seems to find a list of cars that came stock with the GT40s. Anyone have it, or know where to find it?
If you look at the front (end) of the head a GT40 head will have three vertical bars cast in, GT40Ps have four vertical bars. They also have "GT40" or "GT40P" cast in at various places. Early 90's Mustangs had Gt40s, 98-up Explorers had P heads. Here is a good place to compare flow rates of common heads. Pick any two heads and click to compare. http://www.allfordmustangs.com/Detailed/630.shtml
I'm not even involved in this thread and I absorbed the great read! This thread will surely be referred to often. Thanks for sharing your knowledge with us.
I may be mistaken,but having owned some 5.0 cars I believe the only vehicles to get gt-40's factory were '93-'95 Cobras and the early(351W) lightning trucks.GT-40p's came on '97-up Explorers & Mountaineers.The iron GT-40 isn't much better than the E7TE head.The GT-40p is better than both but the sparkplug angle "may not work with some headers"is what they say.I'm a supporter of the E7 heads because 1.you can usually get them cheap,2.they're already set up for unleaded fuel,3.with a good valvejob and exhaust porting they work as good as GT-40's without all the hype.Aluminum heads are good because you can get away with more compression on pump gas,but unless you up your comp. ratio I can't see spending the xtra $$ just to say "I got aluminum heads!"The weight off the front would be a plus though.E7's get my vote for boneyard scavenging,look for '87-'93 5.0 mustangs,don't get '86's,they were little more than truck heads and are not desirable.You should be able to pickup a set from $20-100 depending on condition.Gave $75 for mine & they were usable as is.
So, how difficult is it REALLY to use the GT40Ps? They seem like they should be easy to find. I still have my shock towers, but if I get new heads, I will cut/notch them when the heads are out. Will this help, or is it an "angle" issue?
flow All stock, at .5 lift Head Flow Valves E7E 164.6/114 1.78/1.46 GT40 192/128 1.84/1.54 GT40p 196/139 1.84/1.46
