Thanks for the input Bigdaddy1, do you have a build thread going?
My current plan is to move the Cummins aft about 12", cut into the firewall 4-6", cut 10" out of the long bed to match the un-modified wheel base of the Dodge.
That all sounds like the most work possible, doesn't it?..
I would think, putting the 12V, axles of choice, etc, into the original frame would be far easier.
Cutting out of the long bed, is not going to be easy. It's definitely not easier than going with a frame you can shorten. If you're paranoid, fish plate the seams.
I have talked with a guy that had a newer travelette (72) and used a mid 90's F250 chassis, with the 12V, and he says he wouldn't have it any other way. The swap was easy, the wheelbase was friendly, and he has room underneath to work on everything. If you throw the motor back into the firewall, besides being work, you're going to lose workability.
Besides, those dodge chassis aren't good ones. Front suspension every year whether you use it or not. The only 3 things good with them is axles, and the cummins.