All modern towbars attach to towing brackets or base plates that are bolted to the frame (or front "subframe" structures in unit body vehicles). The usual practice for Blue Ox and Demco equipment is a permanent baseplate of standard width, installed to put the towbar mounting points just below or just above the bumper.
For Roadmaster equipment, the typical solution is a pair of towing brackets bolted to the frame, coming out under the bumper and sometimes the fascia, curving back up to an appropriate height. To these will be attached a baseplate cross-member that comes with the tow bar, although in some recent Roadmaster installations the attachment is a full baseplate, as used by Blue Ox, so the cross-member is a redundant control of towbar spacing. The Roadmaster solution for my Honda Fit was a full baseplate that bolted to the bumper mounts, permanently replacing the crushable bumper with something more solid; for this reason I chose Blue Ox, which mounted the baseplate to the bumper horns, well behind the bumper.
All of this modern towbar stuff, however, is about convenience handling a vehicle that is towed regularly and hooked up and unhooked almost every day.
An alternative solution for vehicles that actually have frames, rarely used for recreational towing, is to install a front hitch receiver, and use a receiver to receiver towbar. I've seen RV delivery drivers using this. You can get front hitch receivers for most pickups and body-on-frame vans.
In the 1950's and 60's we used bumper to bumper towbars that clamped to bumper face bars, for moving around damaged vehicles when we didn't want to use our wrecker. But bumpers were different back then, we could tow most cars with the wrecker just hooking a bumper, or finding an opening in a frame rail. I've recently seen bumper to bumper towbars, and receiver to bumper towbars, in use for towing vehicles of appropriate vintage, i.e. they still had frames.
For towing our (1930-1949 vintage) race cars to and from the stock car track, we bolted fabricated mounting brackets to the bumper horns, as the cars raced without bumpers. This seems to be more like what you are proposing.
You can expect to remove the driveshaft on an Express of that vintage for any tow at highway speeds, or any tow beyond 20-50 miles, unless you can add on a lube pump for the automatic transmission.
For what you want to do, a one-time move, I would rent a trailer large enough to carry the towed vehicle. This class of trailer, in the rental market, will usually have surge brakes. For flat towing, you would have no braking for the towed vehicle. Braking taken care of, I would be a little less concerned about tow ratings, which are largely about managing vehicle longevity and warranty costs, but there are also handling issues, particularly at highway speeds.
Tom Test
Itasca Spirit 29B
