My friend has a 92 Ranger, and I can't tell which MT unit he has...what Is the trick for telling the Mitsu from the Mazda?

It's a 2.3 4cyl 2WD...if that helps.

OK, it's the Mazda R1 I'm dealing with. Does anyone know why it would make a grinding noise in neutral? When you release the clutch, it makes a horrible whine, then bogs out....obviously, it's not finding neutral properly. I understand this unit has an integrated slave cylinder/throwout bearing. Should this be next to replace.

the whine is your throwout bearing, and i would just find one from a junkyard. you would probably spend more money in parts to rebuild what it need then just to find one. i would change out everything i could when you do whatever it is you are going to do with that trans. i hate doing things twice