A Few Questions, on GT40 heads:

Will any GT40 fir my 302? I've been looking for ones on EBAY and some say "95-newer".

What "guesstimate" of performance increase should I expect? Is it really worth it?

One of the auction states: 2- REBUILT FORD 302 GT 40-P HEADS. CAST.# F77E-AA THESE HEADS ARE NOT DRILLED FOR AIR INJECTION AND ARE READY TO INSTALL FITS MOST 1978 UP 302 FORD WITH BOLT DOWN TYPE ROCKER ARMS. 14 MM SPARK PLUG

How do I know what kind of rocker arms I have? Are all 302's 14mm stark plugs???

And lastly, I've done all my mods so far on my truck, I have very little experience with engine work other than the outside components, how hard are heads to install? Just get a Chilton's or Haynes and did in?

Thanks in advance.

 

The gt-40 heads off a 302/mustang/explorer use a smaller head bolt as your 302 does the gt-40 heads off a lightning/5.8 have a 1/2 bolt so it isn't the end of the world should you come across a good set of heads that came off a 351(5.8) you can get special head studs from jegs or summit that have a stepped pattern to allow the larger bolt design to be installed on the 302. Basically anything from 80's maybe down to the 70's had a pedastel mount rockers (bolt down) like yours. You should be able to bolt these suckers down using your manual, the smog issues I can't say, but a best guess would be if you get the gt-40p off a production vehicle then it shoudl bolt down to your truck and keep the emmsions system working or get them drilled as mentioned it is just a matter of connecting the emmisions to the back of the head. Good luck hope some of this rambling made some sense. Good luck, Later

 

See if you can get ahold of the GT-40P heads, I believe they are a little bit better. See if you can get ahold of the issue of Car Craft were they build the 351W. There is some very good info on small block ford heads in there. Good luck!