BTR Brian Tooley Racing LS Hat Valve Seals are work well in original LS truck applications such as the 4.8 5.3 and 6.0 GM Vortec engines found in the Silverado, Tahoe, Suburban, GMC Sierra, Yukon, Cadillac Escalade and more. These are commonly found in the LS6 spring kits with truck camshafts as well.