If you are actually looking for performance out of a SB, why would you not want to spin it over 6000? The heads are the main limit on our Oldsmobiles, be it SB or BB. A ported SB head is not the ideal situation either. I probably should have went with the Edelbrocks my years ago instead of sinking many $$$$ into my #7s which did turn ito a sprinkler system. <<40 year old junk.

 

getting back to the OP, what was the outcome of the new gaskets and maybe head gasket change.

Gene