there are several. check the vendors section. i have the Mark t's. horseapple.com

updated with photo. mine our 41 inch slash cuts with organ pipes welded to the optional silencers. the organ pipes stick ut a addition inch and a half. I also have the bones and the cross over .
adds about 50 hp...lol
John,
I see you have the Organ Pipes inserted, with the left & right sides swapped, from the way I built them. I never tried that. Interesting. I built them so the tubes described a pyramid. I see your install inverted them. Makes sense that would have that effect.
Bike looks good, solo'd with the hardbags and the long pipes with Organ Pipes. I'd like more pics if you get a chance to shoot some in a nice setting.