Doug's Measurement Needed
 

Going to try posting this here:


Anyone with round port Doug's headers on a 64-67 GTO that can tell me what the center to center is on the collectors?

I have D port Doug's and I may be switching to round port heads. Wondering if it will line up to my X pipe.

I know the collectors are 3.5" from the 3", no worries there.

Thanks

I measure 21” center to center on my Doug’s round ports.

Excellent! Thank you!