I have a 2005 Ram Quad Cab 1500 with the 4.7 in it. I can't find any information on the door or in the book. I can say that I have towed a great deal of trailers with this truck. From hauling my 18' fish and ski to hauling a 97 Pontiac Grand Prix on my flat bed trailer from Texas to Kansas City with no problems. Granted I don't use it to pull my 28BH, I use my 99 Z71 with 5.3/4:10 to haul it. With the weight that I have towed with my Ram truck I think you will be fine on flat highway, you will probably suffer on steep inclines but that is to be expected with the 4.7. Happy camping!
Manny, wife Tammy and our son Sammy and our dogs,
Cowboy and Starla.
1999 Z71 Extended Cab, 5.3L, 4:10, with 4" Lift.
2005 Jayco Jayflight 28BH.