How to tell the difference?

[Beezle]

Is there any way to tell the difference between a 5spd and auto 3bolt rear?

 

[essentialDSM]

I'm pretty sure there wouldn't be a difference between 3-bolt rearends, in relation to what transaxle the car has.

However, you might take note that only the 4-bolts were limited slip, and that they are stronger. (Bear in mind that my experience is only with 1st Gen DSMs.) Between 1990 and 1994, nothing much changed cosmetically, but Mitsubishi fiddled with the mechanical peculiarities. For example, I think 4 piston calipers could be had on the front brakes, but only without ABS. And a rear LSD was only available with this but not that, the 6-bolt motor went away in May or June of 1992, blah blah blah. I'd try poking around Wikipedia, they might be anal enough to have tracked that kind of stuff. And I remember a post on these forums last year that discussed just that...let me look and see if I can get you a link...