Ok I picked up a warranty engine from a GM Mechanic and it runs fine and all but it was warrantied because it has a "Ping" in the first cylnder. He says that this is common so GM had to design a special Teflon Piston, is this true?

 

I think all the pistons are teflon coated, to get away from piston slap, but it is not working. mine is a 2002 with 7400 Km. on it and it has piston slap. Check out this web site www.pistonslap.com Chevy. Like a knock!

 

Its a 2002 Engine from a Vette with 1500 miles and I picked it up for $500 minus intake and throttle body.

What is the cure for this, if I decided to go with a stock size forge piston and new rings would that help?

 

'02s have the coated pistons. The coating is intended to prevent the piston skirt picking up on the bore during cold start, since the new pistons run a tighter clearance to try to reduce the noise. The TSB for fixing the ping was as far as I've heard, to measure the pistons, and put the largest one in bores 1 and 8, which tend to be larger. I'd guess that the only positive fix would be a hone or rebore and new pistons.
The real issue is that the LS engines run short skirts, which make them more sensitive to tolerance variations.