1993 Toyota 4Runner Question: Engine Exchange

not difficult if you are a trained tech with electrical experience, the computer has to be replaced and the wiring adapted to fit the computer connectors and the new engine sensor plus there will be extra sensors to install sockets for, like o2 sensors, camshaft sensor, crankshaft ands many more, i have the same truck and i rebuilted the engine for about $800 in parts and 4 days of work, you can find the kit on ebay from many vendors, good luck