Need trailer capacity help-1977 W200 Military Ambulance

From : dumbneasy

Q: ok ive got a rare bird. its a 1977 m-886 military ambulance. its built on the dodge power wagon platform 4 x 4 with a 318 and 727. goss vehicle weight is 8000 with front axle of 3500 and rear of 5360. the only thing changed on my vehicle is that i put in power steering vs the old tug & pray manual steering and went to a 15 inch wheel from the old 17 i want to buy and load up a cargo trailer and i need to know how big i can go. i have no clue. anyone care to throw in their two-cents worth tia .