I'm currently towing with a RAM 1500/5.7, and considering trading for a 2500. My needs don't really require a diesel so I'm looking at one of the two gas engines available. I think either of these eng...
The 5.7 will have a lower GVWR than the 6.4 truck, resulting in about 1000 lbs less payload. The 6.4 gives you 27 more HP and 29 more ft/lbs of torque. I've never met anyone that didn't want an additional 30 HP and torque under factory warranty!
Either engine are good engines though. If the 5.7 meets your needs, its a solid and dependable engine that should be available for a lower price.