No way you would get an additional 10-15hp until you were running much more exotic stuff. As a metter of fact, the entire header will probably add about that. I used the port divider with my Clifford set up. Weld it in there. Good chance it will rattle otherwise, and rattles echo in the header. Sounded like crap.
I'll say. My honest opinion is the Clifford one looks like a cheap piece of crap compared to the Mustangs Unlimited one. Clifford one looks like something they just slapped together and said here it's done... see if you can sell it.
