If I recall correctly there are no companies that allow towing an 80 on their trailers or dolleys. The weigh too much for towing on their trailers. Their opinions not mine. Also, I thought Ryder left the rental business. I know they did in Idaho. Some people I know have told the rental companies that they are pulling Ford Escorts with the trailer when they are actually pulling Cruisers. However, I've heard that this voids the insurance coverage, might even create a liability issue if you were to wreck.
I don't think it will fit on a ryder. I had a 2000 4Runner with 285's and the tie down straps wouldn't fit around the tires. I also overheated the brakes going over the grape vine pass(something like that) near Los Ang. The 4Runner was a tight fit--if you aren't going over any passes maybe you could rent it and drive the cruiser on later and get some chain tie downs......... I used dependable auto shippers to ship my 80--they worked out well.