My tire/wheel size on the rear is as follows: P295/50 R15 Goodyear Eagle II. Wheels are 10" wide with 5" backspacing, in other words, the center of the wheel is centered in the rim width wise. Goodyear no longer makes these tires and I need to replace them. I would like something maybe a little taller, like a 60 or 70 series. My question is, how narrow can I go with the 10" rims? I'm installing 2" drop spindles in the front and wanted to lower the rear 1". Thanks for any help!