I'm assuming you are running a cam something like this....
http://www.cranecams.com/?show=brows...tType=camshaft
Notice that this cam works with a c.r. of 9.5 to 11.0 to 1, so that's where you want to be. If you bore the block 0.030" and use Keith Black part number KB193 hypereutectic pistons with a 12 cc dish, zero the deck and use a 0.039" compressed gasket thickness, you'll have a squish of 0.039" that will allow you to run on premium pump gas at a c.r. of 9.97:1. The only way you can get away with it is with the tight squish.

If you don't pay attention to the squish, then you'd better pay attention to s10streeter.

If you zero the deck, pay close attention to the intake/head sealing to prevent a vacuum leak. Follow my plan....
http://streetmachinesoftablerock.com...opic.php?t=350