Yes another towing capacity question, but a little different...

I'm pretty sure the GVWR and GCWR are primarily based on suspension, frame, rear end (type not ratio), etc. I tried to look up the ratings for a 2000 R/T, which has the 5.9, but it was a two wheel drive, so I don't think that would be useful. I did note that a standard cab 2WD had the same ratings regardless of the engine, 2.4L, 3.9L, or 4.7L. And the standard cab 4WD had the same ratings regardless of the engine. So I'm thinking your GVWR is still 5400, your payload is still 1490, and your CGWR (also called towing capacity) is still 6400.

Thanks. Was hoping for more but will take it!

My '03 4.7L 5-speed 4x4 is rated for a gross combination weight of 10,500 with the 3.55 rear end and 11,500 with the 3.73. But beware, mine has the 9-1/4" rear end (octagonal cover) where older trucks only had 8-1/2" (round cover). Also, in '03 there were brake upgrades and other changes that may have bumped up the capacity.