How big of a tire can I run.
 

I have a set of 15 x 8" draglites with 4-1/2" backspacing on my 70 Challenger.I am currently running 255-60-15 t/a radials that have about a fingers width of clearance between the wheelwell lip and the tire on the passenger side and slightly more on the drivers side.Does anyone out there use the same wheel specs with the 275-60-15 drag radials or similar without hitting the wheelwell lips on the sidewalls??I'd hate to tear up a new set of tires or god forbid my quarter panels.