Michael,
Not sure about using an oval port intake with rectangular
port heads. Doesn't make much sense. The oval ports are
good up to about 6,500 and that is about where the rectangular
port heads are getting started. I would think that the intake
would reach the choke-off point just about when the heads
were ready to go-for-it.
From the number of posts here and on the NCRS forum, it's
evidently quite common to mount a rectangular port intake
up against oval port heads and get good HP up to about
6,500 RPM's. The bolt pattern is exactly the same so there
is no problem there. Just use the rectangular port intake
gaskets if you do this. I will try this myself one day.
It's got my curiousity peaked.
Steve