I didn’t resolve the issue with RNR tires but I did a runout on all four rims from WheelSmith and they were all within their specs so I’m sure it was not the issue. Thinking back, a couple of years ago, I had the same tires balanced on the old rims (8x15”) by a local garage and they also had an issue balancing one of the tires, but were able to get it done, so the issue is with the tire and RNR.
The rims from WheelSmith fit perfect with plenty of clearance for the caliper. They are 15” x 6” with 3-1/4” backspace which I believe is their standard backspace for that size.
I bought their Artillery rims but their smoothies (similar to OEM) use the same outer rim so the fit will be the same. They also sell the center cap and beauty rings to fit and they are really nice.
Phil Moderator, The Engine Shop, Interiors and Project Journals
1952 Chevrolet 3100, Three on the Tree, 4:11 torque tube Updated to: ‘59 235 w/hydraulic lifters, 12v w/alternator, HEI, PCV and Power front Disc Brakes Project Journals Stovebolt Gallery Forum