Gotcha yeah I heard people say that those 4.0 V6s actually tow pretty decent for a V6. Im sure a lot of people will tell you otherwise but long as your trucks got trailer brakes I wouldn't see a problem with it. You aren't hurting anybody if it takes awhile to get up to speed and I am not sure what your wheelbase is on that truck but mine is as much as a fullsize truck since its a quad cab so im not worried about trailer sway. Only thing I need now are some air bags, I got coil overs but it still feels a little bouncy when towing and that's with the jeep on the trailer right. I did let my buddy borrow my trailer to tow home his zj with his taco with a V6 and he said it was less than ideal but it got the job done. I have no complaints towing with my truck, the V8 helps a lot if I need to, I can accelerate just as fast as traffic loaded down but I like to make the truck work as little as possible so I keep up with traffic when towing around town but let the d-bags that floor it from every light have the left lane. On the freeway I usually just sit in the right lane and cruise at 65 and it cruises along just fine I barely have to touch the gas.
I didnt even know they put the 3.9s in rams, damn I bet that thing could barely get out of its own way! When I was looking at buying a truck, V6 was not an option since I knew I would be hauling and I just love the roar of a healthy V8. I test drove a 3.9 dak because it was in mint shape with low miles, took it around the block and tossed the guy the keys back. It was a dog. I ended up with the truck I got cause the guy babied the hell out of it, oil changes every 3k, all fluids flushed, he knew dodges rep with trannys so he had the tranny pulled at 140k and a transgo shift kit put in (truck now has 160k I bought it at 145k) and it felt like it had twice the power as all the other 4.7 daks I drove. I can punch it and it will spin the tires through 2nd, I love it! I almost bought an 01 Dakota back in the day with a 5.9 V8 in it but due to other issues the deal fell through, but my current truck feels just as powerful. Not sure what it is if its the mods I have done but I can keep up with my friends 5.9 ZJ off the line and at a freeway pull we are dead even.
1996 XJ on 36" TSLs, 4", locked F/R, stretched