High Compression Head

[jeepguy1948]

I’m curious, do the “High Compression Cylinder Head’s) as sold by Snyders etc. have a different combustion chamber than stock or are they just shaved stock type heads? Put a different way; can you make a high compression head by shaving a stock head? FWIW, I already have one of Jim Brierly’s heads, I don’t actually plan to do this, I’m just curious.