I think you will be ok but as is stated you are right there and could go either way. I can say I have 10.0 with my 906 heads and I use the quench dome pistons from KB to get .040 to .045 on the eng. And I run 38 total and I never even begin to have any spark knock , rattle , detonation or whatever. I do agree a larger cam to bleed of some cyl press would be a good idea. Ron