Oops!

We were all ready to put the transmission back together when we had a scary realization: the LSD isn't going to fit. After doing a little research we discovered that the S80/Y80 transmissions had slightly different guts depending on whether they were bolted to a B18B (non-vtec) or a B18C (vtec). The B18C transmissions got a different final drive gear, pinion shaft and different bearings. The final drive gear is on a different bolt pattern than the B18B version, so we can't swap our final drive gear onto the B18C LSD.

We were basically left with three choices:
1) Put it all back together with the old diff and give up on our dream of LSD.
2) Buy a final drive gear and pinion shaft (~$800) and turn our transmission into a B18C version.
3) Get an OBX LSD (~$350) for the B18B and sell our B18C OEM LSD.

#1 is unacceptable after all this effort. #2 blows our budget. That leaves #3. We heard enough scary stuff about the OBX during our research that we went with the used OEM unit in the first place, but now it's looking like the only option.