Designed as an upgrade from the plastic OEM timing chain covers on 1996-up Vortec Small Block Chevy engines - Replaces GM part numbers 10244600, 12523972, 12523973, 12558343, 12562818, & 93800970 Excellent upgrade for Chevrolet Performance crate engines that use the plastic timing chain cover Available for EFI (with crank sensor provisions) and carbureted applications (without crank sensor provision) Includes over-molded FKM oil seal, virtually eliminating concerns of the seal spinning out at high temperatures, which is common with other aluminum timing covers Timing indicator cast into the cover – Intended for use with 8” Vortec balancers and other popular 8” aftermarket balancers