Inliners International Forums General Discussion Hi Performance GMC/Old Chevy Single Headre Design Questions.

Thanks again for all the help.

I think I need to make header #3 smaller. I wonder if there is any info available on the optimum size header for a single cylinder of 50 cubic inches running at say 3500 rpm?

I have noticed the 454 chevy v8 headers I see seem to be about 1 3/4 OD. They service 57 cubic inches and off course turn much higher rpm than my old GMC. Maybe a 1 5/8 or 1 1/2 OD header pipe on the single ports would be ok for the GMC?