MAHLE Full Set Right and Left Side Piston w/ Rings STD. MAHLE Original pistons are OE quality and have the same great OE features such as compensated ring grooves to assure proper ring loading and oil control, as well as expansion controlled designs for small fitting clearances to reduce engine noise, wear, emissions, and improve oil control. These are a great replacement pistons for the LB7/LLY engines. They come stock as 17.5:1 Compression Ratio.