Volvo did install the M47 behind a few US 740 Turbos in the late 80s. Not many, though. There are a lot of rumors about durability problems. I know there were at least two versions of the M47, and that the later one was improved. I do not know the changeover date. I also do not know whether it has a speedo drive gear or whether some speedo drive can be easily adapted. The M46, by the way, was also improved over the years. In general, the M46 is a strong trans, when well serviced and maintained. There were a couple of different OD fitted and apparently the shafts do not match up, so you should look into this if you buy a salvage M46. Obviously, it would be risky to buy another 82 M46 because it would be over 20 years old. I would do some research on them and try to figure out what I would need to do to put the newest one in. That mightbe from 92. John Sargent would be a good information source on what is needed. You can mix and match parts, but for an 82 you need a speedo drive and I am not sure the late M6 have that. The 740 M46 work with a different tailshaft housing. Best to learn all this in advance.

Another possibility is a Ford T5. John Parker is working on a conversion. Doug Kauer should be the first one to fit it to the 240, and he has not started yet. It should work, but a few bugs will probably have to be worked out (like clutch, cable or hydraulic, throw out bearing, shifter, etc). I would wait a couple of months to see if this is a viable alternative in terms of price. Used T5 are cheap.

Philip Bradley