Quote Originally Posted by stotzbotz View Post
My heads were serviced before they were installed and the person who did them made the comment that the seals appeared to be in good shape.
This motor was set up for racing about 20 years ago and has solid lifters, high performance springs and cam. I am still getting some blow by and when I run it for a while I'm noticing an oily film on top of my driver's side valve cover that probably originated from the valve cover breather..
Define "the heads were serviced". The person who serviced them didn't replace the seals??

Pull the plugs, see which one(s) are oily / sooty / black.. or, If you can pull the headers or manifolds - see which side has an oily look / carbon buildup. it should confirm which cylinders are allowing oil into the combustion chamber. As far as a good gasket, only 1 name worth anything in my book, Felpro.

I'd just pull the heads and have the stems inspected and replace all the seals with new, this'll also give you a chance to inspect the intake gaskets you seem to fret over.