P heads

[RustyRed]

Will GT40-P heads work on a '66 Coupe.

I had generally heard to stay away from them but if memory serves that is mainly because of having to have special headers to bolt up to them.

Local person is selling some P's in really good shape and including the stainless shorty headers.  Might not be such a bad deal if they headers come with them....

Just wondering would they fit in a '66 coupe or are there any other issues I am not thinking about?

[Fast68back]

Do you have a picture of the headers? My understanding is that there are no headers (early or late) model that will work in an early mustang. Quick google search pulled up other forums with the same questions:

"FOR ANYONE INTERESTED IN GT40P HEADS PLEASE READ.....

I consider myself not too bad of a mechanic... please heed this warning even with an older mustang GT40 (P) specifically those heads are not too good of an idea..... they are great for FOX body mustangs with shorty ford racing headers but remember that even when using try-y stile headers like the ones used on the Shelby GT350s the position of the spark plug on the number 5 cylinder WILL NOT CLEAR THE HEADER!!!!!!!!!!! please dont make this mistake..... I have a 1967 coupe with a 1993 cobra 5.0 block that i built myself...... used GT40P heads and had to cut and re weld my headers... yes the try-y...... also with the use of the try-y header make sure that if you have power steering that you buy the lowering bracket for the header or your driver header will not fit... it will not clear the power steering rack..... this amongst other reasons are why i no longer have power steering......
IF you can afford it buy other heads..... OR be ready for no manufactured headers to fit.... body style may have changed on the outside between 65 and 67 but not the engine bay.... good luck and let me know if you have any other questions about your swap....."

http://allfordmustangs.com/forums/classic-tech/78528-gt40p-heads-into-65-a.html

https://www.fordmuscle.com/forums/all-ford-techboard/415874-gt40p-heads-65-mustang-header-solution.html

[Starfury]

There are headers for P heads in classics, but they're pricey.  FPA and Doug Thorley both make a set for P heads.  They're really nice headers, but you have to decide if you want to spend that much just to get a set of "ok" heads.

The other option is to cut and weld a set of tri-y's to clear.  One of the guys on Mustangforums did that and it turned out ok.  Not amazing, but ok.

The shorty headers that come with the heads likely won't fit your '66.