Nahbro. Differential is where the HICAS actuator bolts on. Sway bars will be different sizes, but I'm assuming you're gonna be looking at them "bare."
But the differential mount points will be a bit different, IIRC. I believe the TT is a little higher mounted and a bit more spaced out, but don't take that for fact. Looking at the FSM, I found this, if the wheel hubs are still installed:
http://www.300zx-twinturbo.com/s.manual/ra/008.gif
I know there are other differences, like the E brake hardware, but again, if you're shopping bare subframes, that won't help much.