I currently have a Mickey Thompson L series on the rear of my 72 Cuda and I plan to get some new tires over the winter. 275 60.15 was the plan until this past weekend. A guy that I met has 255 70.15 and I like the look of the slightly narrower tire. His tires run around 10" width verses my almost 11". His tires are 29" tall vs my 28".

Anybody else running this tire size on the rear of your E body.

Also, with a 3.91 rear gear what would a 29" tire roughly bring the effective rear ratio to?

I know from rpm calculators that I would drop about 100 or so rpm with the taller tire.

Thanks