[brando]

How many types of GT40 heads are there? What does each code mean and what are the advantages of one over the other? Also, I know some of them come stock on some Ford vehicles. Which ones came on what vehicles? One last question, how noticeble would a GT40 heads and intake swap be?

[84 predator mus]

5 different types of gt40's , you got the standard gt40 irons which were on the 93-95 cobra's and the 96-early 97 explorers. the gt40p's are on the later 97-2001 explorers, gt40X aftermarket, gt40Y (aftermarket i think?), and the gt40Z. the Z is the only one that comes with 2.02 intake valve when you buy it new, the gt40X is 1.94 intake, and the gt40 standard and P's are 1.84.

i might be off on one or the other but i think its pretty close to what i typed.

[FoxChassis]

The Ford Motorsport SVO catalog was actually the first place GT-40 heads were found. They were originally designed to go on the twin turbo 351W engine in the 25th anniversary concept car built by Roush but that engine never went into production. The heads were later released for sale through FMS SVO. Look for an F1ZZ casting number.

The '93-'95 SVT F150 Lightning, early, '97 Mercury Mountaineer, and some marine 5.0L and 5.8L engines had GT-40 heads as well. Cobra heads were milled slightly more than Explorer/Mountaineer/Lightning. The difference was about 3cc less for the Cobra version than the others.

The late '97-'01 Mercury Mountaineer also had GT-40P heads.