IN YEARS gone past, the hardest part about an engine conversion was physically fitting it in. In some circumstances you’d need an adaptor, which added expense and an extra step but wasn’t an insurmountable problem. When engines became electronically controlled things got a little more complicated and required extensive wiring, but they could essentially be standalone units – yank out the existing engine wiring and ECU (engine control unit) and put the new stuff in.
Things are now a little more challenging. The original offender was electronically controlled transmissions running their own ECU and needing to communicate with the engine’s ECU. In short, some transmissions simply couldn’t be paired with some engines, even if you could physically connect them.
To make things even more complicated, most currentgeneration 4x4s run what’s known as a BCM, or Body Control Module. They’re essentially an ECU that controls anything that needs controlling. Headlights, air-con, windows… even shifting the transfer case from high to low range. Conversions into modern 4x4s need to not only power themselves but trick the stock setup into working as well. It’s the main reason modern engine conversions are getting harder and harder.