i am going with wiseco pistons.. but was wondering what bore to get?? 95.5 stock bore?? or 96mm with a .020 over?? what are the advantages of the .020 bore?? this is for a shortblock... thanks

 

96mm is 0.020 over stock bore, 0.020" = 0.5mm. I wouldn't recommend stock bore block and pistons you should use the 96mm pistons and have the cylinders bored 0.020 over and honed so the rings can seat properly.

 

^^^^

+10000

0.020" over is typically used the first time a block is re-built.

 

Yea you should go with 96mm, benefit is basically, bore the cylinders and get rid of imperfection as well as make sure its 100% round, you usually cant just put in stock size pistons without resurfacing the cylinders. basically what was mentioned in previous post

 

You also gain 60 ish cc of displacement!! WOOHOO!

 

There is no way to insure precise and correct piston to wall clearances, without a .020 over piston, and the associated machining. Although standard bore pistons can work, it's not a chance I would take or you may end up with some cylinders slightly tight, and others too loose.