Allows the use of 1986-earlier Small Block Chevy crankshafts and oil pans (with 2-piece rear main seal) in 1987-92 blocks (with 1-piece rear main seal). Billet aluminum adapter is machined to accept the factory oil pan seal, instead of having to fill up the adapter with silicone. Includes fasteners, and will work with pre-1980 oil pans.
Converts one-piece rear main seal on 1986 and newer Small Block Chevy blocks to the old style, two-piece rear seal when installing the old style crankshaft in the newer style blocks
Available for use with both new style oil pan (1986 and newer blocks with one-piece rear seal), and old style oil pan (pre-1980 blocks with driver-side dipstick)
Manufactured from billet aluminum