I have a 1984, Landrover, 109, Series 3, Factory Rover V8, 3.5 litre. Does anyone know if a later model Defenders 5 speed gear box will bolt straight on it with out to many complications ? ive been told that possibly a 5 speed Celica gear box might. Does anyone know about that ? and does anyone have any experience with having a quick shifter auto in one ?