I’ve know many of the Paxton and Vortech guys for years so I have a little history with them. The Ball Drive Paxton’s were notoriously unreliable, inefficient and generally short lived. The old Paxton guys (Mr. Joe and Vince Granatelli) used to refer to the “spring-pack” SN60s as the best of that breed, tension on the balls (used for step up) kept them from slipping in the races, lasted longer, made more boost.
I think all the bracketry for the small blocks is on the shelf. BB not so much, but its not a huge deal. I don’t know about the availability of the “Cobra” hat (carb box)
The gear driven blowers are just so much better. I have an old V1 with a T trim impeller and scroll that has 50k miles on it. Still quiet, still makes 10 lbs. Not gonna see a ball drive ever do that, nature of the beast.
Jason