You probably want to contact them via e-mail, I think I filled out a contact form on their website and that's how I got in touch with them.
Calling was a lost cause, nobody was answering.
And Frank hasn't come back into this thread for quite some time, so I doubt he'll come back at all.
If you can still get your stock driveshaft back, I would do that.
If you have no resonators in the exhaust there's enough room to swap driveshafts without dropping the exhaust.
Pretty easy job to do, especially if you have tall jack stands or access to a lift
