I used the M101 US Mil trailer frame as a basis for a trailer to put a truck camper on. It is 96" long and short of 45" wide for the basis of a trailer frame.
I strongly suggest that you replace the heavy tongue, axle and tires with something more appropriate.
I added the front tongue from a box boat trailer frame. I added a Dexter 3500# axle with brakes and 14" tires using the stock leafs. I added 2x3x.25 to fit inside the boat tongue and went back to 2 crossmembers. I think this single post added a lot of weight to the trailer. I estimate the rolling trailer to weigh 800#s.
I added a Quicksilver truck camper on top. Its a canvas top slide in camper. It was 79" overall length.
You can also get rid of the leafs, but this ran so well I kept them. I would look at removing totally or replacing the crossmembers with something lighter but keeping the exterior of the frame secured. They are welded in. The major frame is welded together, the tongue is bolted on, and the suspension is riveted on. I drilled the frame to be able to adjust the axle 20" forward/back at 5" intervals.
I just recently sold the camper/trailer. It was 1300#s empty (camper 450#s) and was a bit much for my 4cyl TJ with coolers, clothing, firewood, Jeep spares, and tools.
I'm working now on an idea with a PWC trailer and looking to add a long bed fiberglass contractor work topper. I'll add a base and sides and bolt it on the frame. It has dual rear doors and 2 large side access doors. I'm looking to build slide out cabinets behind those access doors.
This should be a lot lighter. I'm also changing the 4cyl out for a 4.3l in the Jeep. That will take some time.
