The riceburner crowd uses pourable polyurethane to fill in the pockets or to completely replace the rubber in a worn-out mount. It's available from Devcon in many different durometers. It is also available from Energy Suspension, they use a different manufacturer than Devcon. Do an online search for pourable polyurethane and you'll see there are several manufacturers. As many of the PPs are used to make molds for concrete shapes, find a product that does not include mold release agent. You want it to stick to your metal surfaces, at least I do.

Also review the Shore scale. That little letter, A or D, tells which of the testers to use for that material. IIRC Shore A is quite a bit wigglier than Shore D.

Finally, to do a really good job you need to have a vacuum pump. A Mityvac will work, although it's not ideal. A vacuum pump for an air conditioning serviceman would be about ideal.

www-cdr.stanford.edu/biomimetics/documents/material/PolyU/PolyU

I have researched this pretty thoroughly because my Taurus SHO has a bad engine mount and it's unique to that car. There are no more NOS for less than $200, and the parts store pieces aren't any better than the ones slagged here.

One last thing: I would not recommend using The Right Stuff for this task. A tube of Tremco Polyurethane Roof Sealer might possibly work, though.

R.