[sourdough]

Look at THE truck you intend to buy and look at the yellow and white sticker inside the driver door that gives you the payload and other weights. The weights you listed for payload seem a little suspect to me so do your research. All of those numbers depend on body style, bed length, drive train, trim etc. I don't know, nor have I looked at, the new truck payloads with the 5.7. It appears to me that you may be looking at numbers for different style trucks..I don't know.

All that aside, I think the 5.7 for that trailer (if you never get larger) is fine. I've owned several 5.7s and liked them all. Look at the rear axle ratio. With a trailer that small a 3.55 will work fine, a 3.73 would be better. The new 8 speed is a gem. I would think the payload of the 2500 would increase more but I don't know. Look them over and do your research. I've owned GM trucks, dozens of new Fords and now Ram trucks. I have chosen Rams. They all have the pros and cons.