1st Gen Ram Tech'93 & older Rams: This section is for TECHNICAL discussions only, that involve 1993 Rams and older. For any non-tech discussions, please direct your attention to the "General discussion/NON-tech" sub sections.
I've pulled 6500lbs or so of Ramcharger and trailer with an '83 2wd 318 2bbl and no trailer brakes. Was a load for 153 axle twistin' hp to pull through hill country. Stayed in second gear on the floor @ 40-50mph uphill. Stopping/turning was an experience too. Nearly took out the gate in my driveway, shoved the tail end of my pickup sideways in the gravel. Stood on the gas and prayed,missed the corner post a good half inch.
I'd guess with trailer brakes and careful driving 4500lbs shouldn't be a problem if your bumper is stout enough. Wouldn't exceed 600lbs tongue weight.
Murphy's Golden Rule: A $2500 TV will protect a .50 cent fuse by blowing first.
The condition of your ball and bumper will have something to say about it...
I know my 93 has chugged along with a 3 ton load.... split 1/3 bed, 2/3 trailer there abouts... but the trailer that was used was short, so balancing on the axel was pretty easy.
*by chugged along... I mean 4th gear (is electronic O/D was turned off) at 40-50 (county road limits) used a bit more gas than normal, but way less than if we had taken the 94 F-150... and it would have taken two trips.