Nobody makes aftermarket mounts that I know for the 4wd...have you tried tightening the big nut& bolt on the tranny mount? it gets loose over time. If you have dual cases do you have 2 mounts as well? Are you'r engine mounts worn or broken? Are you using a low profile drain plug? aftermarket crossmember?
It sounds like you have more drivetrain movement than there should be.......But you were not very specific on you'r drivtrain setup here....
