GTO Greg is right,you need to measure the deck height and CC the heads to get good CR numbers,otherwise it all amounts to guessing.
Most Speed-Pro pistons are appx. .020" in the hole on uncut decks,and occasionally more.
And most iron heads are actually bigger than their "nominal" CC specs most sources quote,so the only way to know this for sure is to measure it.
All this needs to be known to get reliable numbers.
Not to mention the fact that there are a couple of different style of those pistons,some have a "bevel" around their perimeter that adds some volume as well,so that needs to be known as well.
HTH.
__________________
This space for rent... 
In the meantime,check out the cars HERE.
|