ok guys i am needing a list of what all vehicles came with GT40 heads. im going junkyard hunting this next week. this is the list i know of..

Mustang Cobras 94-95s
F150 Lightnings 93-95
Explorers ? on years

are there any others im missing???

if yall could also fill in the blank on the years the explorer 5ohs came with them.

 

What heads are installed on a marine 351W with 4 bbl?

 

you mean a 351W HO out of an 84-87? it would be the same heads as any other 351W of that era. i ran into that also.

i bought a 84 351W HO and thats what these GT40s will be going on..

 

It's a marine engine bought from a marine distributor 6 years ago. I assume it is like HO but hoping some of the Gurus will chime in and tell me some about it and maybe answer you as well. It is supposed to have a 4 bbl on it but all I had was a 2 bbl intake and carb. And wondering if this is going to screw me if the ports don't match. Or do they?

 

they should match. 99% sure on that one.

 

Okay thanks I will know soon as i will free it up, button it up and fire it up in a few days.

 

The GT-40 heads came first on the 1993 Mustang Cobras as well as the 1994 & 95 CObras. The first generation Ford Lightings & and the early V8 Explorers as the later ones got the GT-40P heads. The P heads require special headers!

 

So what is on the marine 351W?

 

well check the casting number on the heads. you can pull the valve cover off and it should be on the head just under the valve covers.

 

No.. head casting numbers are on the lower(head gasket) side between the central intake ports, so the intake has to be off to see it with the heads mounted. As stated the mid '80's 351HO didn't get anything special for heads.. usually the regular production E5TE truck head.

The Explorer 5.0 got the GT40 head in '96 and part of '97 only, after that it got the GT40p version.

 

huh?...... the heads that came off my 351W H.O. werent the original E5 heads, they were D8 heads and they have 78 casted right into the top of the head..

the second pic is hard to see. but its D8 something. but thats on the bottom of the head below the exhaust ports.

 

Heads could have been changed at some point or you got an early motor, in any event the '78 head is essentially identical to the '85 head and neither are anything special. Earlier heads did have some identifying casting numbers on the top surface as well but that practice seems to have stopped in the '80's somewhere.

 

ok. that is a good possibility. the engine came out of a very very early 84. like one of the first produced with the HO 351.

 

ok..... so........ i just talked to a friend of mine, he thought he had some GT40s and he checked and didnt. but....

he did have some DO 1970 heads that had been reworked to run with out leaded fuel.

they have been sitting for a while so what would need to be done to have them run with out issues on EFI?

 

Are they 302 or 351 heads? These should have "302" or "351" cast into the top surface around the rockers somwhere, and the difference is the 302 version has 58cc chambers and 1.78"/1.45" valves while the 351 has 60cc chambers with 1.84"/1.54" valves. If they are complete with valves and springs they're a decent upgrade but if you have to buy valves don't bother, you can have CNC ported E7's that will easily outperform these for $600 from Powerheads or Thumper Performance!