KD4UPL wrote:
GM may have changed with the newer models. Back around the '07 to '10 era the 3500 SRW trucks had heavier rear springs, larger higher weight rated tires, and wider wheels to accommodate the tires.
If the truck had a diesel then the 2500 and 3500 rear axles were the same, the AAM 11.5". If the truck had a gas engine then the 2500 got the lighter duty AAM 10.5" and the 3500 still got the 11.5".
So, if you're looking at gas trucks you might be getting a lesser rear axle, springs, wheels, and tires. These all add up to lots of money to upgrade.
I'd keep looking for a competent dealer who wants to sell you a truck.
If I were a dealer I would be very skeptical of anyone dealing exclusively on the phone. I wouldn't think a guy was serious about buying a truck unless he came on the lot and talked to me in person. That's just my personal feeling on it.
18" (17" also?) wheels are the same for '11-'14 2500 and 3500 srw trucks (may be the same for '15), but 20" option only on the 2500.
As mentioned, if a gasser, different axles, but the same axles for the diesel (2500 and 3500). Not sure about the extra leaf vs top overload spring.
Good luck!