After all that fuss to see if the M41 I had purchased from a 1975 240 would fit in my '73 142, it turns out that the M41 is damaged. Somehow the flange that bolts to the output shaft of the overdrive, is bent, probably from the tranny being dropped during shipment. The force to bend this flange, which is solid steel about 3/8" thick, would have been substantial, so now the whole tranny condition is questionable. I have a very nice M46 tranny that I got out of an '83 245. Will it bolt up to the bell housing of my '73 B20? Is the input shaft of an M46 the same as an M41? In short, can you use an M46 on a '73 142 with a B20 engine?