I'll have to re read,I though it was with 1 7/8 on the dyno. Whether his or theirs, if both @ 1 7/8...I wouldn't expect it to make a giant diff aside from collector size and length..but that's just what I'm thinking...and not end all.
Yeah, I can’t remember what he said. But the BSFC numbers get pretty high and that could be the headers pulling air and fuel right out of the chamber and into the exhaust. Or it could be something else.