.............. and they say he's full of shit Kahill Smith replied................. I just opened up my Mopar Engine Carroll Shelby's Speed Secrets book from Direct Connection and it states on page 44, section E for Pistons and Pins , the 3rd paragraph that "Factory pistons have the pin offset to reduce piston slap. By reversing the offset (reversing the piston) engine friction can be reduced. In engines equipped with power pak (domed) pistons this can be accomplished by installing pistons from the right bank in the left bank and vise versa. This means the notch in the edge of the piston top will now be toward the rear of the engine. With two barrel flat top pistons , it is only necessary to reverse the piston pin on the rod and not necessarily to swap from bank to bank. A piston to bore clearance of .0015 - .002 has proven to be adequate with stock type pistons. Race pistons do not have a piston offset and there-fore don't need to be reversed. " That was a lot of typing for me.