Check your tranny mount too - most likely its not helping keep everything in place, puting more strain on your engine mounts.
I've got some of these:
http://www.summitracing.com/parts/ptp-1-503-bl/overview/make/jeep
~ $100. They have lasted ~ 10yrs behind my stock 401/T18/3.15:1 Dana20, but they are starting to fail now.