I believe the stock gasket for the rear housing cover was a thick gray paper, not cork. But I'm sure cork would work well. Keep in mind it's all in how you prepare the surfaces and gasket as to whether it leaks or not.

Here's NAPA:

FEL-PRO Gaskets

PART #

FPG RDS5088


Craig

My '50 Chevy 3100 5 window, '62-235cu, 3:55 rear
My truck ....... Respect The Rust
If I'm not working on my truck, '65 m00stang or VW camper, I'm fishing with the wife or smoking Salmon.