Originally posted by John H. Meredith:
Dear Rob;
I'm not sure what the "best" seal is etc.
John: Here's the Best Brand gasket setup I used:
http://www.oldGMCtrucks.com/photos/gmcforum/302/BestGasketRearMain.jpg The NOS rope seal is about 4 thouandths proud, but no more. And there is black RTV on either side of the cap by and around the seal ends to further seal it. I am again very confident that no oil is getting by the ends on the top between the mating surfaces. This problem appears to be scrubbing the seal itself and runout continues to be high on the list of suspects.
Check out that
Best Gasket setup. These guys have a pretty good product design, and many of our oldGMCtrucks.com forums members are running these successfully in their 270's and 302's with no leaks. This engine is just a nasty bugger that wants to drive me nutso; and so far it's been doing a bang-up job!
