Justin, the answer was too long to go on a PM.

can you figure the compression Ratio using this piston? thanks[/QUOTE]
Sure. I'm assuming these are flat-tops with valve reliefs, right?
Multiply .7854 times 4.04 times 4.04 times 3.75 times 16.387 and get 788 cc's in the cylinder.
We know there are 72 cc's in the chamber and 5 cc's in the piston eyebrows.
We know that a small block Chevy is 9.025" from the centerline of the crank to the decks if the decks have never been cut. If we deduct the 1.425" of compression distance on the piston, 5.7" inches of rod length and half the stroke (1.875"), we are left with a piston deck height of 9.000", meaning that the piston will be 0.025" down in the hole at top dead center. Multiply .7854 times 4.04 times 4.04 times .025 times 16.387 and find 5.25 cc's in the piston deck height. Assuming a gasket with a bore of 4.200" and a compressed thickness of 0.039", we multiply .7854 times 4.2 times 4.2 times .039 times 16.387 and find 8.85 cc's in the gasket.

Now, add 788, 72, 5, 5.25 and 8.85 to find a swept volume of 879.1 cc's.

Now, add 72, 5, 5.25 and 8.85 to find a compressed volume of 91.1 cc's.

Now, divide 879.1 by 91.1 and find a c.r. of 9.65:1