If you look closely, you can see it appears the Genaddi header system is very similar to the Stainless Works (SW) basic header. Connecting to this basic tube header system and replacing the stock cast iron manifold, SW offers a straight back piping addition direct to the bumper exhaust outlet area, or a Random Technologies replacement high flow catalytic converter with straight back outlet pipes, both of which connect to the headers with collector adapters.
Update: In fact, it appears the header part of the system is from Stainless Works...note the label on the headers. The collector ends appear slightly different than the SW photos, but their pieces differ depending upon whether or not a cat or long tube component is part of the system. Genaddi may be the same, and the header back part of Genaddi's system may be different than SW's, although I haven't seen pictures to compare. SW may not have the polished tip option, which does look nice on the Genaddi's. Perhaps the folks from Genaddi can speak better to this issue?
The pricing from SW on the complete system including cats is $2413.95; the system without the cats is $1993.95; headers only are $1573.95. Ceramic coating inside/outside on the headers only is an additional $300.00.
A far cry from $5100.00 for the Genaddi system, although I don't know if that price includes the coating and/or installation.
A further updated note: The final outlet exhaust passage hole in the stock cast iron manifold, as you look back into the oulet, appears only slightly larger than the sizing of a single cylinder's exhaust outlet hole. This means the combined volume of four cylinders has to squeeze through a final passage about one-fourth the size of their total volume. At high RPMs and high flow, and with all due respect to others on this forum who have argued headers add little to performance, I don't see how a good set of headers cannot contribute in some manner positively to the engine's performance.
I understand these folks are going to be running a detailed evalution of the FRPP long tube headers conversion and the SW header and header/cat system options, including construction quality:
www.fordgtsupercar.com Click on "Automotive Systems"...