OK, so I don't know much about Oversize or Ballooning tires much.

Short story, I got a '88 Pickup (3vze). Looking to mount at least 2 newer (new-ish) tires.
Wondering about putting 325/60R15 (LT) Tires on a 15" (x 8" [?] ) rim.
Wondering about Ballooning/Clearance, as well as Power/Weight.

Currently I have 31/10.5 R15 on 15 (x7 I believe).

I did the math (Sorta) and checked clearance with a Super High Tech - Straw of grass, to the chassis and Springs.. Figuring If the Tire center were offset by about 1", The Tread Should clear, about a half inch from the out-most protruding bolt on the leaf, where I think, I currently have about an inch and a half. I can further clear that bolt by flipping it. But, how much will the tire balloon in the walls?? Will tire weight difference strain my engine, Trans, or Gear box? And In 4Wheel drive does it matter that the rears might be heavier?

Anyone have pictures?

 

Most of us run tires in the inch dimensions if you can post up specs in inches would help. Pull the specs from the manufacturers page as each have slightly different.

You have to watch out with moving tire with backspacing, backspacing is easier to understand than offset. Depending on how you intend to use rig, you can cause tires to rub on outer edge of fender when fully stuffed. If you are gonna stay on road won't be a big deal.

 

Just under 31 inches, run em you will be fine.