My dad has a 05 2500 duramax 4x4 quad cab. He is looking to lift it and put some bigger tires on it. His previous truck was a 2003 duramax leveled with 285 75 r16 bfg muddterrains on 16x8 wheels not sure what the offset was. The truck really looked good with this combo but he was unhappy with the ride of the leveling kit. This time he is looking to go with a 4" rancho now I am in charge of finding him some tires. What is the biggest tire you can fit with a 4" lift on an aftermarket 16x8 or x10 mickey thompson classic 2 wheel. I know it would probably be somwhere between a 33" and a 35" tire but I need to figure that out in metric tire. If anyone one is running this lift and is running a nice looking wheel and tire combo please let me know what you are running and post pics if you have them. Thanks

The Rancho 4" is really designed for 285 tires. I ran 315/70R-17's tires for awhile but felt they were just too big and required some trimming and still occasionally rubbed. I have since switched to 16x8 wheels with a 5" offset and running BF KO 295/75-16's and feel they are the perfect size tire for the 4" Rancho...however they are so close to 285's I doubt a person could tell the difference. Personally I wouldn't go with a 10" wheel. Coupled with the fact the Rancho spindles place the wheels outboard 1.5" per side you would end up with a real "bulldog" look and have 3" of tire sticking out past the fenderwells.

I have 295 nittos on 17x9 rims looks and fits very nice. He will like the ride of the rancho, my only suggestion would be get the 9000 adjustable shocks instead of the 5000 that come with the kit.

I have since switched to 16x8 wheels with a 5" offset and running BF KO 295/75-16's...
I see you have the Ultra Magnums in your pictures, sweet looking wheel.:ro) You wouldn't happen to know the weight rating for those wheels would you? I can't find any mention of the weight capacity on Ultra's web site. Thanks.

Nick Frank from Ultra Wheel just emailed me and said 3,000 lbs on the load capacity. Hmmm, thought they were more then that but I'll never tow anything real heavy.

On edit:

Received more info from Ultra wheel regarding the load rating on this wheel.

The 16x8 8 lug with a 4 1/4 inch backspace has a 3400 lb rating

The 16x8 8 lug with a 5 1/4 inch backspace has a 3000 lb rating

The 16x10 8 lug also has a load rating of 3400lbs.

Check Sig..... no bumper trimming, only trimmed some of the inner fender trim, but mine is also an 02, newer bumpers need a little trim on lower corners, GMC's need plastic on lower corners trimmed

boss's 05 GMC ccsb dmax/ally with 4" rancho, 315 tires(35's) , 17x9 wheels fits very well with just a bit of bumper massage

we've found we can get almost 6" front lift with rancho kit by cranking T-bars, we usually start at 4 turns above stock and usually go down a bit from there, wherever customer wants it