What's your goal for the motor mounts? More strength? You might try Rockstomper or others similar poly mounts.

Another cheap/free thing you can try is chaining the stock mounts. Roger B has some info. I've been doing that on the Runner, but my crawler still kinda overpowered them because it generates so much torque. I just put in a FROR t-case crossmember to control that though, so it shouldn't be a problem anymore.

'97 4Runner, '06 F350, '86 4Runner, '05 WR450
http://home.4x4wire.com/erik