Is your valve cover bent/warped ? I had a leak, cleaned up the valve cover and a nice new cork gasket fixed it... Be sure not to over tighten screws/nuts on your valve cover... That can cause them to leak too...
1954 Chevy 3104 3 Window Hydra-Matic in my family for over 60 Years
Once in a while you get shown the light in the strangest of places if you look at it right... "Scarlet Begonias" Grateful Dead 1974
