Do I have to have a lift kit
 

I am new on this forum, I have a 2006 hummer h2 and I am wanting to put 26x14 inch rims and 37.50 inch tires any recommendations on a lift kit or how high of a lift kit would I have to get. Hopefully a 3 inch would be enough.

I'm looking to do the exact same, did you get this figured out? I'm being told a minimum of 5 inch lift but I'm hoping 3 inch leveling would work.

37.5" tires will fit with a levelling kit but will probably get a tiny bit of rubbing in the front at full lock in reverse.... that is how mine was and was just fine although I did not do rubber band tires, I did 37's on 17's. I also only cranked the front keys 2" on mine so it would not ride like crap and not wear the front end out super fast which will happen if you crank the front keys to the max. What will probably make the difference on yours is if the wheels you get do not match the same offset/spacing as factory.

37r12s. A man of taste… and sidewall.