The Stovebolt Site Forums The Shop Area Engine Shop 261 Rear Main Seal Leak Fix

Group 0.137 SEAL, Crankshaft Rear Bearing & Cup Oil

Take you choice - both styles are listed.

NOS part #3812855 (see it listed at the link on the first line, above).

Make your choice, take your pick, keep your fingers crossed.

I found an old post here where I indicated /confirmed that the seal I used in my 1960 261 (in 1972) was the rubber-style seal. That engine is in my 1954 Suburban, and, it is not leaking, yet.