opinions on hooker headers

OK I found what I think will work for my 67 cuda on Mancini.


Comp 66-77 A, B, and E-Body A-engine 1 5/8" x 3" (Ceramic Coated)
Competition Header, 67-82 Mopar A, B, E & F Bodies: 273-360, Tube Size 1.625" O.D. x 34", Collector Size 3" O.D., Collector Length 8", Port Shape: Same As Port, Metallic Ceramic Coating.
$389.95
HKR5901-1

The ones I found on Summit is part 5204 which are 1 3/4 tubing. I guess that's where the horsepower comes in and the extra cost.