You will not get a big response since the question you ask requires clarvoiancy on our part. But....I'll try to help.
Assuming you have a .030 overbore on your block, you have a swept cylinder volume of 727.41 cc's.
Presuming your block was not decked any or very little, you have a deck height of .020.
This is about 4.4 cc's.
Presuming you will use a .041 compressed thickness head gasket, this will be 9.1 cc's.
Presuming you have a cheapo cast piston, it's probably got an 11cc dish and a ring land volume of 1.5 cc's.
Using a total volume of 753.41 cc's plus a 58cc head, we get 753.41 plus 58 divided by
58 + 4.4 + 9.1 + 11 + 1.5
Equals 811.41 divided by 84 = 9.66 to 1
Perfecto Rocky, but you'd best find out for sure if those pistons are really the 11cc dish type. A flatop will make much higher compression. Also, that .020 deck height is a guess. It could be anywhere from .040 to zero.
There are far too many presumptions in here for me to say "go for it" right now.
The S/R torquers are "stock replacements". You may want to shop for a set of Corvette 58cc heads instead, since those S/R's need to be fully ported and polished before you see a big power increase.
[This message has been edited by Box of Rocks (edited January 30, 2001).]