So basically 2 weeks ago, the M47 gearbox from my 1991 240 Estate with a little more than 200k km started whistling in all gears, safe for the 4th, which I understand it's the direct drive. Also there's a bit of rumble in neutral with the clutch pedal released, that started at the same time, so it's probably not the clutch bearing.
A quick look on the Volvo forums and volvotips.com suggests it's probably a shot bearing in the gearbox. Did not check the oil yet, to see if it comes clean or with metal debris, but I guess it won't matter too much since the gearbox bearings are discontinued (checked with the local Volvo garage) so rebuilding it is pretty much out of the question.
Found a replacement gearbox at a local junkyard, coming from an 2.0L petrol 1987 740, which looks almost identical, 5-speed, bellhousing, mount, and so on (at least in pictures, local means around 300km from my current location, so I did not go to see it live) but the code on the gearbox is 1 023 561 ,while mine is 1 023 608 P15.
Is anyone here that can tell me if it's the same M47 as mine, I know they came in 2 versions, M47 and M47 II, and I guess that this might be M47 first model, and mine probably M47II, but the real questions is, IS IT an M47, and will it fit the current clutch?

Thanks a lot.