Used Aftermarket Aluminum heads.

[ken-r-mer]

I'll have to get back to TR Designs to see about a larger pulley (my error in the previous post, had a senior moment) for 5 lbs boost to run on 89 octane or stay with the 6-7 lb boost and run 91 octane.

And if I stay with the current piston that was installed in a professional rebuild, 12,000 miles ago by the previous owner, I can determine the radius by the chord formula method knowing the diameter of the piston and the height difference between the piston rim edges and at the center. Then just add 0.40" to the calculated radius and thus the radius of the required cutter bit for the head cut to be parallel to the piston radius.
Since the cutter bit will flush out the cut to the head surface, to maintain the 0.040" separation at the piston perimeter, Cometic makes 2 compressed thicknesses for piston rim maximum upward heights being below the block deck surface, one being 0.027" and one 0.036". Then one compressed height at 0.040" for a piston perimeter being flush with deck height. Finally,7 compressed thicknesses for piston perimeter heights being above the deck height from 0.051"to 0.140". All gaskets being MLS (multi-layer steel) comprised of 3-5 layers.
I'm learning why the various thicknesses are on the market.