Ricatic nice to hear from you.
MeAgain is correct.
I will tell you what I know having owned a 11 HO RAM Dually 4x4 68RFE with 3.42's towing a combined 29K for more than 1/2 the 65K I owned it. Vast majority of my towing both rigs is West Coast.
My Current truck is a 15 RAM Dually 4x4 AISIN with 4.10's towing a combined 33K or 35K when double towing my MC trailer. Hand calc depending on load is 8.5-9.
The 11 did a GREAT job hand calc average of 9.5 towing at 60-62mph. The ONLY negative was taking off on a grade of any kind you had to ease into it to get it rolling then let er rip.
The 15 even with 35k on any grade and some were fairly steep the truck simply took off with no shudder.
I towed the 11 in 5th at 60 it would be about 1,750rpm's a perfect towing rpm's. The 15 in 6th is about the same rpm's.
The 68 stayed cooler than others I read about most likely since I had added a MagHytec double deep trans pan.
The AISIN stays cool in any conditions! 170's are the highest I have seen even towing in 2nd on 14% grades for several miles locked in 2nd in higher temps.
So you are looking at towing a 20K 5er. My rule of thumb and it's similar to RAM's list 28K combined or less go 3.42's it will perform just as well as the 4.10's but with MUCH better mileage solo. Anything over go 4.10's and don't get sucked into the "Compromise" of 3.73's!!! It will but you out of the sweet spot. They will do the job just NOT as well.
AISIN is a TRUE Medium Duty trans that will get you a higher HP/TQ MediumDuty Cummins, WELL worth the extra $$$. Someone mentioned a more expensive service on the AISIN all I can say to that is "Whatever" !!!
So I would say based on your RV weight and the truck weighing about 10K 4.10's are the way to go!
Now for the details, the LongHorn with the good grill not the Limited grill!!! Also I HIGHLY recommend the Factory Rear Air Ride. Three years now and not a bit of an issue. I run mine in "Alt Ride Mode" ALL the time.
First pic is truck in Alt Ride and so is second with 9,750# on the 4 rear tires. Alt ride will give better solo ride and also makes for easier entry and exit. Truck rides much lower than regular sprung trucks on the rear.
The leather on the LongHorn is available in two colors, the lighter is not available with the stitching but the darker is like mine. The QUALITY of the leather is TOP cabin sorry guys but it does put the leather to shame in the Laramie models.
I am spending the time here for you Ricatic because I truly hope you get a truck you can depend on and are happy with!
Oh the exhaust brake is AWESOME!!!
Any questions PLEASE ask! Great call on the B&W puck hitch.
