Bingo,I thought those CS cams seemed a bit more than I'm wanting.But I mentioned them as,well this one:
BBC 454 to 470 CID with GM Edelbrock Roval Heads to a max of 6000 rpm - Clay Smith Cams
is said to be catered for the heads I have.I'm seeing the same with pistons being catered to these heads:
https://www.summitracing.com/parts/SRP-212135-8/
something to do with the spark plug (hole) being more toward the center of the combustion chamber (now I hear this after it's been a couple of months since I got them).I'm hearing that 10-10.5 cr is tolerable in an aluminum head...9.5 as a precaution to bad fuel ?