The swap to the long shifter is straightforward. Having the cover off will allow you to look for any chipped gears. I don't recall if the reverse light switch is located on the shift extension--if so, you'll have to mount the old style that has the contact behind the reverse shifter rail. That should also be a straightforward swap from your M40. If you need one I think I have a few good used ones. The M40 cover may be already drilled for the fourth gear OD contact--if not I think you'll see a a flat boss where it should go. The transmission removes/installs easy enough to just go ahead and stick it in to see what you have. -- Dave