Get another Moog (or other OEM type) engine mount and install an engine torque strap. These vary from a piece of chain to a heavy turnbuckle. FordMuscle had an article about making one awhile back. Here's the link: http://www.fordmuscle.com/archives/2000/04/quicktips/index.shtml
In my experience, solid motor mounts are hard to come by, expensive and real filling rattlers. I haven't broken a torque strap (or another motor mount) since I installed mine.
I don't think he was talking about a solid motor mount as much as the 'captive' style rubber insulated mount that was standard on the 72-73s. They eliminated the broken-mount totally breaking away, allowing the engine to torque off the mounts. With the captive mount, if the engine mount breaks, the engine is still held in place, but may 'flop' or torque about a half inch.
This style mount became standard after a series of accidents involving engines that torqued up, and continued to torque up because the throttle would stick wide open. The throttle linkage would bind up as the engine continued to rise up off its broken mount. Not a good thing if you're not expecting it!
Before the advent of the captive-style mount, the quick and dirty trick was to put a limit strap, either cable, chain or turnbuckle to limit the ammount of travel the engine could torque up off the mount.
in non-speed-read mode I see that is just what he is asking. Good question, I can't remember the last time I saw captive motor mounts for sale. I have been using the strap trick for so long I forgot that they made them. Thanks for clearing that up.
Back to the priginal question: Are they still available? Does anyone know where to find them?