rim width

Just for future information, in case you get to wondering;
A long time ago,I got the somewhat bright idea to install a pair of 325/50-15 BFG Drag Radials on my car for a quick trip down the track, and see what my beast could do, cuz everyone in town but me wanted to know. I didn't care.
So I mounted them on 10s, with 4.5bs wheels, cuz that used to be a popular wheel combo, moved the springs inboard, and finally narrowed the rear to fit. Then I lowered the car until it rubbed, and pounded a lil on the inboard side, lowered some more and pounded a different spot, until it all played nice together. On the outboard side , it just needed a wee bit, so I just folded the lip up a lil.
Then I put the ride height back up and that was that.
After the TnT, 4 runs, only one completed, I put the 295/50-15s on and there is plenty of clearance inside the stock 68 Barracuda tubs , that; even at my lowered height, I never give those rear wheels any thought, even off-roading, or bouncing of curbs.
Sorry I can't give you a banjo measurement, it's going on 16 year ago, long before I ever heard of FABO.

69 Formula-S's have the best rear view, I installed that same back end onto my 68.