68 Barracuda Fastback build

I have a similar car, 318/904,3.23/8-3/4/BBP, etc.

Buy why did you say you want to get rid of the torsion bars?
The Mopar suspension is superior to the GM and Ford junk of the day and can still hold its own. Don't succumb to the typical TV reality show trash where they always want to automatically replace the suspension. That may be needed on a 68 Mustang or Camaro but your car already has a decent suspension. Set up right you don't need add-on traction bars and suspension relocation. Larger diameter T-bars with good shocks and good rear springs is a good starting point. Make sure all the replaceble suspension bits are in good shape

Look at the Mopar Action Green Brick and check out Jeff's site if it's still up for inspiration. jefframin.org

Good luck and have fun.