Hey ya'all this is my first post so please be kind. I have a 2004 4.6 that is a member of our family. I proposed to my wife the truck was there. At our wedding we drove off in her. Our daughter left the hospital in trucky. Yes we call her trucky. Currently trucky has 174k miles with out ever a complaint. We just purchased a 24' travel trailer. Here is trucky's current set up. All stock motor and trans. Leveling kit with about a 33". Original 8.8 with 4.11's.. Has a edge programmer to correct the speedo and monitor tranny temp. Trucky does have the factory tow package with the tranny cooler.
I have not even picked up the trailer yet but out first trip it to hope valley 7200 ft elevation so I'm stressing about ole trucky. Please if you have actual experience towing with a 4.6 please let me know. And to everyone who thinks I need to go buy a 5.4 that would be ideal and I do have the means to do so but I love my truck my family loves our truck.
I am currently getting trucky ready for the big day. All I can think to do is just another service oil/trans/coolant. I bought a mag-Tec trans pan for the added capacity. Please if you have experience and ideas let me know.

Our trailer is 5100# dry. thank you for reading this and I hope your truck has been as faithful of a family member as ours

 

I don't see an issue as long as you keep an eye on tranny temps. The 4.10's will probably be closer to 3.73's with the 33" tires, but that's still fine. Depending on your truck's configuration (regular cab/scab/screw) you should still have a max trailer weight around 6700-7Klbs all-in. So keep an eye on how much you load the truck/trailer up with gear. Also, I hope you have electric brakes/controller and a W-D hitch, as it'd be unsafe to tow that rig without it.

Otherwise, just watch the engine/tranny temps and take it easy on her. The tranny with 172K+ miles isn't anything to abuse when under a heavy load.

 

O.K. so I made got back from our trip and i am happy to report that trucky did well. i was off on the weight of our trailer it is 5600# dry. i pulled the trailer with the tanks full so 400# in water plus all our gear. i took highway 88 over Carson pass which is 8600 feet. suspension and braking is perfect i was surprised that it didn't effect the ride that much. i pulled the grade in the mornings on the way up the truck was in second gear over the summit and it was struggling the highest coolant temp was 209 and highest trans temp was 226. i have to admit this was my fault. after the truck kicked down into second i pulled the shifter down to hold it there not thinking about the fact that it wouldn't kick down into first. yea I'm a moron. coming back the last part of the grade is 8%. once it started to lug down i put the peddle to the floor, trans kicked down to first. I pulled the shifter down and held it there. only about half throttle held it at 4K and it pulled over it fine at 35, max trans temp 206. i know thats not diesel speeds, but at no time did feel like the truck was taking a beating or did i feel unsafe. i love that damm truck

for all the guys with a 4.6 i hope this info helps

 

If your tranny hit 226 I'd get the fluid exchanged (not just a pan drop, a full exchange with a machine).