The tc and svo run the vam, where as the na cars pre 1990 run speed dencity. The speed dencity is premapped and can not tell if a car is making boost, It will run lean under boost and lead to rapid catistrphic failier. The 90 and newer 2.3l cars ran massair, you could potentualy run that computer but it would requier alot of tuning with a programer and alot of dyno pulls. In short, the turbo computer and vam is the quickest, cheepest, and most direct way to do the swap
"VAM"(Vane Air Meter) is the metal box that goes inbetween your air filter and the turbo, it has an L shaped flap inside that moves when air is being pulled past it as its sucked into the turbo. This is the tool the computer uses to read air flow in to the engine.