15X7 w/4in BS Tire Size Question

Tire 1 245/60/R14
Tire 2 245/50/R15
(Examples: 285 / 75 R 16 or 33 X12.50 R15)


Tire 1
Tire 2
Diameter
25.6 in.
24.6 in.
Width
9.65 in.
9.65 in.
Sidewall
5.79 in.
4.82 in.
Circumference
80.3 in.
77.4 in.
Revs/Mile
789
819


Use this link to mix and match comparisons
http://tire-size-conversion.com/tire-size-comparison/




Here's a quick comparison.
I ran 245/60/14's in my '67 before I had my narrowed 8 3/4 with an offset spring kit and they were the widest tire I could get in there without rubbing. I now run 275/50/15's and they're awesome.
I believe in this case with a stock rear end, spring placement and wheel openings, width will be your limiting factor without any modification.
...Brian