If you re-read what I wrote above I said if the case is bushed, which it is, you could probably get your money out of it by parting it out because it has many desirable race-oriented parts.

That said the pro-shifted stuff has been outdated by the superior "face plate" design. The face plate design uses much wider spacing and bigger "dogs" or lugs that increase durability and the "shift window".

If it was me and I wanted to go bang some gears I'd dress the dogs on the gears, inspect everything carefully during rebuild and run it. It will be really fun to drive!

If you are really paranoid you can have the gears/case magnafluxed. I'll attach a pic the instructions for you.