I need some tire size help please....

[derotoreut]

I don't want to beat a dead horse here, but I'm racking my brain out trying to figure out what tire size I can use on my '69 C/20 8-lug stock ride height. I would like to try the H2 Hummer rims, but don't know how to figure out what tire size I can go with. I'd like to run a bigger tire like 285/70-17, which is almost the same size as a 285/75-16 (which I see many have used). I want to be sure they will fit without any clearance problems on the H2 rims. I was thinking about trying to find some junk tires to mount and try, but I don't really want to mount and unmount tires on these nice rims if I don't have too. Is there anyone out there that can help me?

I'm not sure how stock wheels compare to the H2 wheels, but I've heard they have more backspacing. Here is what I've learned so far about the H2 wheels:

17" Dia.
8-lug X 6.5" BC
4-1/2" Hub Dia.
8-1/2" width (9-3/4" overall rim width)
5-1/2" Backspace which translates to 3/4" (19 mm) positive offset

BTW, I purchased OEM Chevy 16" center caps P/N 9597169 / 9597170 which are 2001-2007. They fit perfectly on the H2 rims with no mods required. I also bought the correct conversion lug nuts.