I don't understand why you would buy a completed short block and then want to begin changing parts, but hey, whatever.
Pay attention to the compression height of the pistons you plan to buy. Stock CH for a 350 Chevy is 1.560", but rebuilder pistons have a shorter CH (1.540") to compensate for shortening the deck height of the block. The shorter CH will make it more difficult to achieve a tight squish. Hang just the tip of one jaw of a dial caliper into the top of the pin bore and the other jaw at the crown just above the top ring. A 1.560" CH piston will measure 1.096"/1.097".
Last edited by techinspector1; 11-12-2012 at 10:03 AM.