Odd noise from drivetrain.

Looking for some help diagnosing a noise from my jeep.

1998 TJ (I know not a Cherokee, its my daughter's)
4.6 Stroker
AX-15
231 t-case
Super 35 with Auburn Ected
no lift

I get an odd "clunk" when going on or off the throttle. It seems to come from the left side near the t-case.

It has done this for a while, I replaced all 4 rear control arms, the trac bar is tight, the diff seems not to have any slop.

At this point I am thinking that it is either the T-case or that one of the mounts for the control arms has cracked.

I will check the mounts tonight, and I am wondering how I can check the t-case at the same time. I will have access to a lift, but it takes a pretty hefty dose of throttle to make this happen. I don't know if I can repeat that by hand.

Thanks for any help

Motor mounts?

Motor mounts had crossed my mind. Thanks I'll make sure to check them tonight.

anything else I should look at?

u-joints or tranny mount?

Ujoints have been checked to death. I looked at the tranny mount and it seemed ok. No cracks or other obvious problems. Will check it close along with the motor mounts tonight.

Thanks