Question: Hi, Please can you inform me if it is possible to substitute the 4-speed Hydramatic gearbox fitted to my 1968 2-door Shadow, with the later GM 400? so far I have spotted differences in part numbers on FS website for the propshaft, starter motor and torque converter, wondering if there is anything else I need to be aware of, thank you regards

Answer: This is the advice from our Technical team: Everything is possible but you would be changing engine/gearbox extension, complete gearbox, propshaft, gearbox actuator, top of column switching and gear change and all other involved wiring circuits