One can buy a nice set of new/fresh iron E7TE's that are ported and polished for around 700.00. Or, for another 300 one can go with GT40 X303 heads. The aluminum heads will flow better but would you agree that the iron heads are more durable and less likely to blow head gaskets and of course strip threads? My goal is to leave this motor alone after it is assembled. In other words, once it is in the car and running I don't want to tear this thing apart for years. Though the aluminum heads may flow better would others agree that the iron heads are more durable? Also, I'll be running a stock GT mustang roller cam so I probably wouldn't use the aluminum heads to their full potential. Thoughts!
For $1000 as your mentioning, Id go w/ the aluminum, but not the GT40 heads, Id get Edelbrock or something of that nature. Aluminum disperses heat alot better than iron, and is less weight. Flows better also. Me personally I'd go w/ the aluminum even on a street motor 1) looks cook 2) works well 3) less weight 4) cools better
my buddy has great luck with the afr 165 heads. stock 88 shortblock, with a custom cam, and an edelbrock 2 efi manifold, 1.6 rr's and the usual bolt ons is putting 325 to the wheels. On a side note, why mess with the e7 heads? 96-01 ford explorers came with the iron gt40 heads (96 and early 97) and gt40p heads 97-01. Happy medium, those heads can be had for $200ish at any truck/4x4 yard, and will easily flow as good or better off the shelf than your $700 ported e7's.
the GT40Ps have modified spark plugs and port design/location? Will headers still fit? Jeremy, any idea what cam specs your friend is running? http://www.powerheads.com/SB50.html not bad numbers for iron E7TEs, flow seems to max at .450 very close to the stock .448 roller GT cam!
I'm not sure on that cam, I'll have to check. good news is, the gt40 heads are pretty common, between the 93 cobras, the 94/95 cobras, and 96/97 cobra's, they're just as common as the 97/01 explorer gt40p's. Dunno though, I've been out of the mav circle till recently. I'm sure there is a few threads here regarding the p heads and header fitment. I'm curious myself. Luckily, clearance isn't an issue with my stang, that's why I can run the fms ceramic shorties, but I doubt those will fit on a mav.
As a side note to aluminum cooling better: This allows either higher compression on premium fuel, or lower octane (cost) fuel if high compression is not your goal. I don't see how aluminum would be more apt to blow a head gasket... As for stripping threads, have you never seen threads strip on iron parts? I have seen plenty. It all has to do with the yay-hoo wielding the wrench. Early 351w heads or GT40p heads will flow best for you if you want production iron... but you will have header problems with the P heads in our cars. I would personally do the aluminum in a heartbeat. To repeat: Lighter (every 100# lost = 10 rwhp added) Cool better (good for either 1 pt in compression ratio, or to run cheap fuel on a streeter) Look cool (unless you want to look stealthy, just paint 'em) Flow better than anything stock. Good luck Dave
I've heard rumors too about head gaskets blowing because of the different cooling rates and expansion rates, etc being different for an iron block, vs an aluminum head, they'll contract and expand at different rates because aluminum cools and heats so much quicker than the iron block which it's bolted to. However, I agree, and it doesn't seem to be an issue with the 302/5.0's
ratio411, I wasn't sure about the head gasket problem I just know that a lot of production cars with aluminum heads and iron blocks seem to have a problem with head gaskets but maybe it is a production problem and not necessarily the aluminum heads. Jeremy, I have heard the same thing regarding expansion rates etc. In my case, the most compelling reason to use aluminum is weight. However, it always seems like the aluminum doesn't hold up nearly as well. Do we have some folks on the board that have run aluminum for a long period of time? If so let us know. Andy, how do you drive that thing on the highway with 4.62s in the rear? slowly?
IMHO, I wouldn't spend that much for the iron heads (ported or not). You can pick up a set of used Al heads (that would probably flow much better) and be carrying a HECK of a lot less weight. Just my Good luck.
I agree with Rick. I just bought from EBAY Edelbrock RPM's, like new, for $675.00 Had my shop check them for flatness and vacuum the valves, no problem. Also, regarding the stripping of bolts, they come heli-coiled..
There are plenty of production v8s that use aluminum heads... Every late model Chevy pickup, for example. The late Fords, based on the 4.6/5.4 are terrible about almost any problem you can imagine concerning the aluminum heads, but that is poor design IMO. I have seen first hand: Spark plugs pulling out threads while running, sounds like a rifle shot. Heads that leak water between the block and head. Heads that go through gaskets due to surface pitting. I wouldn't own a 4.6/5.4 if you paid me. They are junk and give a bad wrap to aluminum heads and Fords in general.
Few things to remember with aluminum heads: Keep fresh antifreeze or additives in the engine. This will help prevent corrosion due to the change in PH levels. Use anti-sieze compound on all bolts and spark plugs. Anything with disimilar metals. Use good gaskets.
good idea Maverick70. Ratio411, I've heard some of the same complaints about those engines. I think the OHC idea is a good one but maybe better engineering is in order. Have you heard anything about PBM (brand) aluminum heads?
Great point about the anti-seize!!! I was thinking about that. When iron/steel bolts are threaded into, or come in contact with aluminum, they have a reaction with each other causing them to seize together. So use anti-seize on any part that has aluminum contacting ferrious metal! That will save your threads. Dave
