I had some others, "Ford Performance" by Pat Ganahl and another I don't recall the title but it was by George Reid. That's the one that has the most mistakes in it, but it's still useful for a reference. I looked up that head milling chart and was wrong. Removing .040 gets the chambers down to 58 ccs on an E7TE head. Should be the same on the GT40. The GTP heads had smaller chambers, they're listed at 58 to 61 ccs.

 

How much milling can you typically get away with before having to shim up the pedestal rockers?

 

If I recall there's only .060" of travel in the lifters , So it's possible you may have to shim the rockers after milling that amount (.040) If you're reusing those stock pistons, I'd be hesitant about milling the heads if using a larger than stock cam. Those reliefs aren't too deep there. The P heads are already about where you need them to be as is.

 

Ok, understood, thank you. I have Explorer GT40's, not the P's. The whole thing is going to an engine shop for machining/assembly/dyno tuning in a couple weeks time, so I'll let you guys know how it all turns out.

Thanks again for all the help.

Rem

 

It's been a while so I thought I'd follow-up on this. My 302 should be assembled next week, and break-in/dyno the week after. Ended up boring 0.030" over and ordering new pistons. Compression is going to be 9.1:1, and I also had to switch cams. Apparently my new Comp 31-230-3 cam had too much run out and it's going back for a replacement. I ended up bumping up to the next XE cam 31-234-3 as I wanted to keep the build moving along. I was going to go with the 35-234-3 or the Lunati Voodoo equivalent, but neither were available quickly, and the 31-234-3 could be had within a couple days. Anyway, the 31-234-3 cam should get me back in the 300HP range and have at least a little bit of a hot rod feel to it.

I'll be back in a couple weeks with dyno results.