Hi: I have a 92 Indy 650. Last year I went threw 2 pistons however in diffrent postions. I,m currently using .020 wisco lites but I,m beging to think there junk. It's not a lean problem as I always check the plugs. They burn down right in the middle. I'm going to install stock .020 this year and install duel fuel pumps as I'm thinking it's a fuel starvation problem.