Part I - Rear Brakes & American TT Wheels
OK, found some time to check things out today as I was installing new shocks and trac bars and started pulling wheels to go through the brakes. So here are the details on the rear brakes and wheels. Rears are stock original drums #3841177 and no spacers were added using 15" x 7" wheels with 3.750 BS

Stock rear drums. No spacers required.

These American TT wheels fit great and look totally at home on a 68.

Wheels are 15" x 7" with 3.75" Backspacing.

Good inside clearance to shocks whether on stock shock plates or aftermarket trac bar applications.