[packratbimmer]

Yes, he means #1 in the pic. The pic is the small case unit. You need the plate from the medium case 188 unit.

If you get the 2.93 from an E28, you will need a rear cover plate from an E30 medium case 188 differential (non-325iX unless you want to change the mount bushing)...or the M or Z plates you mentioned in your post.