Apart from the engine loom is there any other form of wiring that needs to be replaced with the G40 equivalent, ie is the wiring to the rear pump all the same etc etc...
Gav
Genesis are generally later spec so depending on the age of your G40 conversion you may run into late spec-> early spec issues e.g. oil pressure sensors, engine bay/headlight loom->ECU loom mating. That's all I can think of right now
Its an L reg if that helps, im not sure what the age of gar the G came out of
you only need to change the engine side of the loom! and change the fuel pump to a g40/gt pump
there are two looms in the engine one for the ecu main engine loom and 2nd for the headlights and peripherals you may just need to change the ecu loom!