Widest rim and tire for full mini tub to frame

I have run 325 Hoosiers on my tubbed 72 Scamp, they are listed as 13.1 inches wide. With a 1/2 inch clearance to the springs l could still fit my fingers between the outside of the tire and the fender. So I would say a 335 should work if the stars line up... but not ever car is the same