[Automotive Stud]

I think you'll have issues with the starter, the starter is closer to the bellhousing on the 60 but it's probably not something that coudn't be overcome. That said, the zephyr gears in a '39 case will obviously work but the overdrive will not just go on the '39 case. Also as mentioned, the 60 probably won't have the umph to make the overdrive usable anyway.