I have a Motorsports Auto round flange header which I originally purchased to put on my '78 head with round exhaust ports. I have now decided to use the p90 head which has square exhaust ports. I read on one of the Z sites that the round flange header is used for both round and square type of heads. I measured the square exhaust ports vs. the header and the corners of the exhaust port will be covered by the header flange. Any suggestions? I've thought about grinding the header flange to open it up. Should I just buy a header specifically for square ports or is the one I have ok?