The aluminum (or steel in earlier models) part that bolts to the block is (according to toyota) an engine mounting bracket. The piece that goes between the bracket and the subframe is commonly what is referred to as the mount. Toyota calls this part an engine mounting insulator.
51cards is correct, the "insulator" is identical between the later-style 7m and the 1jz. The early 7m used a vastly different type. The 2jz uses a related insulator (i.e. also silicone-filled), but it's shape is different.
IIRC, you can mount a 2jz in a late-style 7m subframe if you use the 1jz engine mounting brackets. Someone correct me here if I'm off...
The early 7M mounts are square and a couple inches shorter than the later round mounts. I believe the later model mounts are 6 inches long...being 1.5 inches of bolt on both sides, and 3 inches of rubber. Good luck finding these. I never could...Ended up making some.