Ive got a related head story .
I built a 440 in the early 90's that didnt run right from the get go. First problem was a bad lobe on a MP 509. After that was replaced the car would fire up and run awful. Wouldnt idle right/stalls....
I went thru everything possible for a long time, and it still acted like it had a vacuum leak or something.
I finally pulled the heads off and took them apart. These were "fresh rebuilt/valve job
/etc.." THE SEATS HAD THE DYKEM ON THEM--- Untouched. So the valves were leaking like crazy .
I took them back to the shop and they did them right and the motor ran great after that(low 12's).

The shop was called Maco Machine in Des moines , Iowa--i believe they are out of business now -- and they deserve it. They cost me a lot of time and mental anguish.