First off, thanks for everyone's feedback and help on this build as the ideas behind it came entirely from members on this forum. This is just a spin-off of AndyF's manifold 400/470 build with cam & head help from Dwayne. Since the 383 is the most common BB out there, I hope other "resto-rod" guys might find the info here useful. A "budget" version could easily be built with offset ground 440 crank, pocket ported iron 452's, and MP528 cam.

So .027 head gasket HP increase is negligible, about margin of error of a dyno test.

Is increase in detonation resistance for tighter quench worthwhile or would I be spending money for no change to go to .027 or .030 Cometics? I'd like to save that money for pushrods if possible.

I basically have 3 Compression/quench options: 10.48/.048, 10.71/.039, or 10.8/.035. I know many have shared that .039 is ideal, anybody have experiences on the trade-offs??