Originally Posted by cobalt327
No need to try to turn the oval ports into rectangular ports- you can't anyway. Just run the intake on the heads, as-is- if you can't get the correct intake to match the heads. There have been reports that this combo works better than you would expect. Use rectangle port gaskets.
I have a pair of these rect-oval ported heads in my "Do not do" archives. Whenever a customer asks about "converting" a set of oval port heads. I show them. A lot of work for nothing. Th only "port match" is at the gasket surface. There isn't enuff material in the upper port to even come close to a rectangle port match.
The Super Stock drag racers in the seventies used rectangle port intakes on oval port heats on a regular basis. I've built a few street/strip BBC's this way and have seen no ill effects. As stated, Just use the rectangle port gasket.