GT40 heads on 5.8
 

Will GT40 heads fit a 5.8 with stock intake and exhaust?

It'll fit the block with I think the holes enlarged but the exhaust manifolds might need to be changed.

I plan on getting headers and a new intake, I just can't afford to by everything at once. Didn't know if the Heads would bolt on the stock motor or if I needed to wait and change the heads, intake, and exhaust at the same time.

GT40s will fit with no issues with the intake or exhaust manifolds. If they came off a 5L engine the head bolt holes have to be enlarged.

GT40P heads have a unique spark plug angle that make them difficult to fit with factory manifolds and many headers. They also need the head bolt holes enlarged.

Do not pay a premium price for either version. Many sellers think they are made of gold.

Not sure if they are the P's or not.

You need to know that vital piece of info. GT40Ps flow a little better than GT40s but they can be problematic to find exhaust manifolds or headers to fit an OBS.

Another reason why I prefer aftermarket heads......

Not paying a fortune. Guy only wants $100.

Just bought a pair of gt40 heads off a 97 explorer. Going on 5.8 I'm building for my signature ride. Paid $96 at pullapart, had 2 other sets there. Lower bolt holes are 1/2 inch already.

I hope it works out for you.