just wondering how much would .006" milled off the head equate to compresion wise? (i.e. 10:1 to 10.1:1 ??)

 

On a 5.7 head .007" is 1cc of chamber reduction, which is around .1 point in compression. So 10.1 comp. shaved .007" would be 10.2 to 1 compression. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

 

My calcualations are a little bit different than LS1derfull but I suppose close enough. When you mill stock head .025, the compression goes from 10.2 to 10.8 on a stock head.

 

I have found the same thing, milling .oo7 is .1 compresion increase and -.720 cc's. I came up with an equation that I use for figuring compression ratio for the stock ls1 that figures in stock head gasket thickness, ring land, and deck hight... 618.475+ {chamber cc's}divided by {chamber cc's} ex. 618.475+63cc's/63cc's=10.817063
there is a longer equation I use when figuring other variables and for my forced induction heads. Milling .035 on a stock head and valves will give you 10.8 to1, My stg2 heads get 10.8 to 1 with .025 mill and larger valves{2.02-1.575}