I too pull a 34RL Cedar Creek with a 2008, 2500, Ram Mega Cab. I changed out my wheels and tires to a 10 PLY Nitto Dural Grappler tire LT285/70R17, 126S with the appropriate rims. This will support a load of 3750 LBS at 80 PSI for each tire, but I run the rear tires at 70 PSI for a combined load rating of 6900 LBS and the front tires at 50 PSI for a combined load rating of 5,510 PSI.
I have run the truck and trailer across a certified scale with the rear axle at 6,100 LBS and the front axle at 4900 LBS and the trailer axles are at 10,000, for a total of 21,000 LBS.
Hope this helps.
Jim & Jill
Sold: 2010 318SAB Cougar:New: 2016 Cedar Creek 34RL. 2008 Dodge 6.7LCummins the original 6.7L engine, w/68RFE Auto