FLAT TOP 292 CHEVY 6 CYLINDER PISTONS, Highest Compression possible. .040 Over. Check out the pictures in the photo gallery for a comparison between the factory compression piston, The Silvolite High Compression Flat Top Piston and the Sterling LPG High Compression Piston. Great for racing or any other performance application. This is a matching set of .040 ever pistons. The ring grooving is the normal specification so you can use a stock ring like a Hastings number 668. Custom designed for Rigney Auto Parts. This piston is a higher compression than the LPG piston that Sterling made, look at the pictures below. These are cast pistons. The compression ratio is 10:1.  These are cast pistons. And they do indeed use the same ring that a stock 292 piston uses. The Hasting # in 668.  When the 292 was still in production we would buy new factory motors and rebuild them for maximum performance. Silvolite made these flat top pistons to our specs, but we would have to order 150 sets at a time. The last run of these pistons was made in 1994. There are 4 sets of .040 pistons left. There aren't enough of the motors around to ever make another run. The .040 Pistons weigh an average of 1025gr.