what are the gains on these babys.. and if i went to the junkyard what do i ask for? what car do they come of? thanks

 

yeah i would like to know also i found me a set that have about 2000 miles on them and was wondering, i am going to get them anyways because i know anything is better than stock but what can i expect....some mods i have.....cobra upper and lower intake, hypertech chip, ram air kit with k&n filter, b303 cam, bbk longtubes with bbk o/r x-pipe, and underdrive pulleys........just trying to figure out about how much horsepower i might gain with these

 

actually pretty good , you just need to do a little work.

my buddy went 11.80 on box stock gt40 intake, gt40 iron heads w/ very mild port work on exhaust, slight decking, 4.10's and 125 shot nitrous

the heads off a '93 cobra , f3zz casting are what you want.

 

I hate giving away my little secrets, but look on car-part.com. It's a listing of nearly all online junkyards with some pretty sweet deals if you have an interchange manual and dig in it.

 

96-97 explorers with a castin # starting with f6 or f7 and gt40p's on 98-01explorers have a # f8 and also gt will be cast near the headbolts(near exhaust) for gt40s and gtpwil be cast in the same place for the p's

 

imo gt40p head is the way to go, a buddy of mine got a set off of a 98 explorer, put them on his 92 5.0 convertible with an auto trans. the engine has a mild cam and bbk shorty headers, car made 345 at the wheels and ran 9.4 in the 1/8