The Brian Tooley Racing (BTR) LS Rear Engine Cover Gasket (BTR39249) is engineered as an OEM-style replacement for GM part numbers 12639249 and 12633578, providing reliable, leak-free sealing for the rear cover on LS engines. Designed for popular LS platforms ranging from 4.8L to 6.2L, including LS1, LM7, LQ9, LS3, and others, this gasket maintains proper oil control and rear cover alignment during engine operation. Manufactured from high-quality materials for excellent heat and oil resistance, it is ideal for refreshes, rebuilds, or routine gasket replacement. Whether servicing a daily-driven engine or maintaining an LS swap, this gasket ensures consistent rear cover sealing backed by BTR quality.