I have finally completed my driveline upgrade to go along with my M44 Frankenmotor. If you HATE the huge gap from first to second gear on the 240's, I highly recommend this swap. I will outline a few things needed to do it.
You need the cut the shift rod and shorten it. The way I did it was to cut it too short, run an 12x1.5 tap into each end and then screwed all thread in. This allowed me to test-fit it few times and after I adjusted to the correct length I then welded it together.
The e30 alum shift base works perfectly.
I loosened the driveshaft nut and slid it all the way together, moved the center support all the way back and has a few mm of play overall in the driveshaft length. It works but just barely, and I have no noises or vibrations after 3 months or so (3k mi)
You have to use the g250 slave cyl.
With a 3.25 out back, it feels like it has the perfect ratios to me. Granted my eng has more torque than a standard m42.
Hope this helps anyone considering an e36 m42 or m44 swap. Just use the gearbox too! You will love the close-ratio, I promise. You can test drive mine if your in the Sacramento area to try it out.