Total seal Classic Race conventional ring set IMCA circle track 604 crate engine. S/B Chevy 350/ Bore size 4.000″ File fit set +.005″/ Top ring 2.0mm thickness ductile iron plasma moly face /Second ring 1.5mm thickness cast iron/Oil ring 4.0mm thickness stainless steel standard tension. Applications street ,drag ,circle track, mild nitrous, forced induction sold as a set. (Note check your piston ring grooves dimension before ordering.) Please e-mail with questions and available.