I thought I'd share a surprising finding regarding the industrial head vs. the standard Go Devil head.
I cc'd each head, and I found that the Industrial head combustion chamber cc'd to 87.5 cc's.
The Go Devil cc'd at 91 cc's.
This was for #4 on both heads. I did the measurement twice on each to be sure.
Calculating the compression ratio assuming a 0.070" thick head gasket, zero deck pistons and ignoring the volume taken by the valves sticking up above the deck of the block, this calculates to:
6.68 to 1 with the Industrial head, and
6.48 to 1 with the Go Devil head.
So, despite the Industrial head having a 0.065" dish around the complete circumference of the cylinder (the Go Devil has no dish around the cylinder bore), I can see that the "bowl" of the Industrial head ramps at a much shallower angle to the spark plug zone compared to the Go Devil ramp in the "bowl".
But getting back to the gasket situation, I received the "copper" gasket from Walck's today. I was pleased to see that it is made by Best Gasket, which I believe to be a good company. I've used some of their stuff in the past.
The copper gasket is two sheets of 0.010" copper sheet sandwiching a graphite center. One copper sheet wraps around the other around each cylinder opening to serve as the compression sealing rings.
As for the fit, it does have a wider opening for each chamber compared to the Fel-pro gasket. In the picture below, where the machinist rule is, comparing the width of the chamber opening for the Best Gasket and Fel-pro, the Best Gasket is wider by almost 0.060" at that point. (Which means the gasket is further away from the edges of the cylinder and combustion chamber.) This is what I wanted.
Best Gasket recommends Permatex Copper Spray on the gasket, so that's what I will do. Not sure when I'll put it back together as it's below 10 deg F out there for a few days even at the height of the day. Too cold to paint heads or mess with copper spray!
I'll update again....