I'm currently rebuilding a 455 for my cutlass and I am now to the point of assembly. My concern is the rear main seal, I know that the stock replacement seal is a rope seal and I am wondering if anyone knows if there is a rubber rear main seal made for the 455's?

 

Two questions to help your question is it a one piece rear or a two piece? 79 was a transition year. two piece is usually just the oil pan side leaking. one piece drop the tranny down and back and let the engine settle back with the engine hoist and you can get to it. two piece un bolt oil pan and the two lower timing chain cover bolts and drop pan and put in new gaskets.

 

There is so much wrong with that last reply....

1. They last year of the 455 was 1976.
2. Oldsmobile never made a 1 piece rear main on any V8.
3. Transition year????

If you go anywhere looking for a rubber seal for an Oldsmobile you won't find one, but a lot of guys are running a Ford seal, but I can't remember which one. I think it's a 460 seal but don't quote me in that. So long as it's for a 3" main bearing you'll be fine.