Thread: GT40 heads

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Looking for info on a GT 40 "X" head. Anyone know much about'em? I'm thinking they gotta be better than my smog motor 78 heads!

They make a really nice street head, for racing they run out of room at about 7,000 rpm, but that's well beyond normal street driving requirements! I've ran them on a couple engines, best results were on a 302 that was bored .030, flat tops, in a factory roller cam block with stock (reconditioned) rods, and a Comp Cams cam. Left the valves stock, with a 3 angle valve job and the valve springs that Comp recommended for the cam. (could probably dig up the specs if you want them. Had an Air Gap Edelbrock Performer RPM intake and an Edelbrock 600 carb. Had the engine with a Top Loader 4 speed in a little '79 Mustang. Pulled strong through all the gears, had the usual mild cam idle, and when going down the highway at a reasonable speed (70-75mph) would still pull 20+ mpg with 3.50 gears!!! Never did take it to the track, but with street tires I think it would have been a solid mid 13's car. Nothing outstanding, but an excellent driver and still enough snot to play a bit..... Way, way better then your smogger heads, for sure!!!!

WOW, that's a boatload of info! Thanks. I'll see if I can get them for a good price as I knew they just gotta be better than the stockers on there now!

Thanks Again,
Mike