These pistons are available for 948cc,1098cc and 1275cc engines. You will have to let us know what size you desire. Rember to bore the block when you have the pistons in your hand - not before! These are a special order items. They take about 3 weeks to have made for you. So, plan ahead! Venolia pistons are forged aluminum alloy thus are measurably stronger than cast or even squeezed cast. They do not need anything fancy in the ring department. Deves rings will work just fine. These pistons are fully machined and have tapered Max light pins and pin oilers. The 1275cc pistons use the thin Cooper "S" rings.