i'm wanting to put after market tires and rims on my 03 dodge cummins, slt, quad cab 4x4. i'm going to stick with 17 inch rims. might get dished out rims. what will be the largest tires i can run without rubbing? i know i might have to do little work with the torsion bars to level out front end.

 

If you have a Cummins you don't have Torsion Bars, you don't even have an Independent Front Suspension so unless you buy a leveling kit there is no way you are leveling out the front end.

I believe that 35s will fit, or at least I know they will on a 1500, with a little cranking of the Torsion Bars, so I don't see why they wouldn't fit a 2500 that sits higher.

 

315's will fit.

Saint is right, the 4x4's have a coil over shock front end with a solid axel. the 1500's are the ones with the independent front end. and a leveling kit is the only way to accomplish this

 

i have 2" coil spacers on my 04.5 and i was told when i ordered rims/tires that the biggest i could go with no rubbing at all was 33/12.50 - 17 on 17x9 rims. i believe i could've fit 35's with no trouble, however, off roading or hard cornering might make 35's rub. don't forget that your OEM shocks are not designed to extend that extra 2", so take that into account. i went ahead and put Ranchos all the way around and love it.

 

I've got 18" rims with Nitto 325/60/R18's (2500 Ram 4X4 Cummins SLT) and all was good, 325/65/R18's rubbed. I might add that these tires (any brand in this size) are very very hard to find. From what I was told, Toyo and Nitto are the same company and only make this type of tire in Japan from January to May, remachine and make their performance car tires the rest of the year. I had a good friend at a tire shop look for 4 days for me. He rounded 4 of them up for me (in October) from 3 different shops in California, Georgia, and Michigan. Thought I was gonna have to buy some factory take offs (my came from the dealer with this size tire and after market wheels). Whew................