275/60/15 sidewall clearance to leaf spring clamps- suggestions?

Looks like you have it figured out. But wanted to point out.
When you take the 275-60r15 off that are on 15x8 with 4.5 inch back space. And put the 275-60r15 on 15x8 with 4.25 back space you moved them to the quarter panel not sure how that plays in, my cars tight, real tight
I removed my 1973 Dart Sport 340 8 1/4 321:1 suregrip.
And installed a 8 3/4 Moser BB axle with green bearings, 11" drum brakes ( Sea Body, Van, Truck ones)
I am at max at wheel lips and close to springs.