Thanks Gerry, I have read postings where some Dodge website links are listed for reference but none worked.
As for my truck it is 07 SRW short box mega cab 6.7, 6 spd AT and I think I saw 3.73 on the door tag.
I looked at the owners manual and I could not find anything in there.
I also read that towing max is mostly governed by the GCVW, I saw 20,000 and 23,000 so I am not sure what my truck really is?
My guess is GCVW 23,000 minus the GVWR which is curb weight plus fuel, pass and truck cargo which would leave about 14,000 for the trailer, is that just about right or is there more to it that that? Is the trailer pin weight(fifth wheel) added to the truck GVW before you subtract from the GCVW?