The shifter of the M46 and M47 pops up in the same spot. But in both cases the tunnel had to be enlarged (a bit higher, not wider), a custom crossmember had to be fabricated and the right lenght driveshaft had to be made.
Since both my M46 and M47 had the larger type flange on the tranny I used a complete drive shaft from a 240-series (cut to the right lenght though). This also ment changing the support bearing and the flange on the diff. You could also weld a 'big type' shaft to the 'small type' so you don't have to change the flange on the tranny nor the support bearing or diff flange. Like so:

BTW. If I were you I'd just use a B21/B23 bellhousing and put the tranny on a slant. My M46 ran much nicer slanted then my M47 does upright. Saves the trouble of getting a custom bellhousing. You just need to change the shifter position. Like so:


Cheers, ben

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P131, '65, B20B+M47. P131, '69, B20E+AW71L+LSD. (www.tinustechniek.tk)