Updating this thread...(I'll upload some pics, but here is what I found)
R150 tailhousing will fit the Post '95 R151 trans with a couple issues:
Must use a R150 tailhousing bearing (this bearing sits in in the tailhousing near the shifter)
Need to modify the shift fork/lever (R150 has fat shifter lever inside tailhousing, R151 has slim lever)
Edit: tail housing swap will not work between post and pre 95 R150.