My boat is powered with a GM ZZ502 block with Edelbrock Performer RPM D port heads. I am swaping out the Mercruiser cast manifolds with CMI elbow top headers. Problem is, round tubes on D ports seems like a mismatch! I don't know if I should use round gaskets or square? Can I expect any problems with this set-up? Is there anything I can do about the mismatch?
Thanks a heap.