Some one else will have to chime in here with direct experience.
My take on it is that the blocks are probably the same on the inside, but I can not imagine that all the bolt hole are in the same place on the outside since the engines are turned 180 degrees in the EVO with the cylinder head turned around to keep the exhaust ports facing forward.
Even if the EVO block does work, the EVO transmission is made to mount on the driver side of the engine bay. So unless someone went to major feats to turn your whole engine arangement around, the transmission in your 1992 DSM must go in on the passenger side of the engine bay. You best bet for upgrading is to set it up with EVO 3 gearing or an automatic if you dont like to shift. The EVO 3 had the same engine config as the DSM. I believe that it is still cable shifted but with stronger gears and double synchros it's the best thing this side of a DogBox.
FYI- A re-man EVO 3 trans is in the neigborhood of 1700-2500 depending on what you want. You can have the stocker rebuilt with new synchros here locally for under $350 if you take it out and put it back in.
Oh and welcome to DSMCentral! Cool name.