2016 Ram short bed 6.7 diesel 2500 payload close to max

The 3500 SRW and 2500 are very similar trucks. The payload rating is limited on account of the 6000 lb rear axle rating that the 2500 gets vs the 7000 lb rating of the 3500. The axle rating is reduced on account of the spring rating. Put a set of air bags on your 2500 and it will handle your Grand Design better than the 3500 SRW with higher payload numbers.