I have a th350 to AA d300 adapter... Normal wheeling and the tail of the th350 is cracked around the 4 bolts for the adapter... I also tear alot of motor mounts.
I already have welded chain across them.

My question is can I solid mount the 350 SBC and th350/d300 and stop the torquing(sp) and twisting of the tranny mount? Square tube instead of my poly mounts?

I have a 6 point cage solid mounted to the frame (no bushings) and a decent crossmember/skid plate aswell. I hope this will keep any excesive frame movement to a minimum.

Thoughts?

I have a th350 to AA d300 adapter... Normal wheeling and the tail of the th350 is cracked around the 4 bolts for the adapter... I also tear alot of motor mounts.
I already have welded chain across them.

My question is can I solid mount the 350 SBC and th350/d300 and stop the torquing(sp) and twisting of the tranny mount? Square tube instead of my poly mounts?

I have a 6 point cage solid mounted to the frame (no bushings) and a decent crossmember/skid plate aswell. I hope this will keep any excesive frame movement to a minimum.

Thoughts?

Well, you can but it will start ripping stuff apart. Rather then the bushings absorbing all the shock and torque, it will be transfered to your frame and crossmember. Eventually, something will break....probably the engine mounts themselves.
you might think about useing rubber bushings for the tranny and keeping poly bushings on the motormounts. This way, the motor will (in my own logic) twist around less and yet, the tranny will have more play with the rubber bushings......because it sounds to me like you have much more engine movement and the tranny mounts are minimizing that end of the powertrain.

Might be worth a try.

Is the torque arm that is stock on a CJ7 a good idea to keep? or can I use another pice of chain ??

I think I will try a rubber mount instead of the poly tranny mount.

By torque arm, do you mean stabilizer bushing?
My AA adapter (T18a/D300) is probably like your adapter i suspect, with 2 bolts spaced a couple inches apart. That should eliminate the need for a stabilizer bushing (one bolt for the mount, one for the bushing). But i suspect you get less movement witht he AA adpater settup then with a stabilizer bushing. That could be creating enough rigidness to allow the engine to break your tranny houseing
I would try the softer rubber bushings on the tranny mount and see what happens. Minimizing movement on the engine side is your best bet though....that tears up bushings and other things quite fast. Maybe some poly bushings as i recommended earlier.