Best All-Around Tire Size?

[guruerror]

If you don't want to lift/level your truck, then 315x70Rx17 are probably ideal to avoid excessive rubbing.

If you don't mind tweaking the torsion bars or adding some Truxxx/GM-Green keys then I would say 37x12.5s are the way to go. The little extra added meat under a basically stock-height truck looks pretty badass IMO.

If you're gonna lift it then the sky's the limit...

Keep in mind; as your tires get taller, your MPG gets smaller.