Rear Tires/Wheels-67 Notch

Need some input on these wheel rim setup.Anyone with some advice to bounce off me would be great.
Trying to figure Centerline Convo Pro's on the rear of my 67 Cuda.
Stock leaf spring setup.
15x8 have a 4.5" backspace and 15x7 have a 3.375 backspace.
Going to run 255/60-15 BFG's on it.Not many choices with this SBP setup.
Looks to be real close to leaf with a 8" rim, good room towards fenderwall.
7" rim gives me clearance near leaf but pretty close to the fender.
Leaning towards running the 8" and using a spacer if I had to to push away from leaf a bit. Probaly only 1/4" -1/2" spacer.

Thoughts??? Any body else done this crazy stuff???