Tires rub, buying new wheels, but unsure.

[muddpile]

Well, I've spent 3500 miles in the driver seat this year, and have found a few little problems with my 72 C10 long fleet. The truck has 15x8 70's/80's style rallyes on it right now with 255/70/15s all around. The front tires rub when I hit low spots in the road and at full lock when turning. They rub top outer edge for sure, as the undercoating is gone. The truck has an ECE 4" spring/spindle front drop, and a 6" leaf-flip rear drop.

I want to upgrade to a set of 17's. The set I've picked out are 17x8 with a 4.5" backspacing. I will be running these all around. Will I have any problems and what is a good size tire for an application like this? Thanks!

The wheels will be wheel vintiques 66 series rallyes (or 68 if I go chrome). If anyone has any pics of these on a 67-72, that would be great. Thanks!