The center driveshaft mount is different. Instead of being mounted in a rubber retainer which is bolted to the tunnel with a strap clamp, the bearing is bigger (same ID) and pressed into a metal plate which is held to the frame with two 3/8" pins through rubber grommets (same grommets used to suspend the exhaust in some 1800s). The later front shaft can be used but tne nut needs to be modified (made thinner) and I took the 3/8" pins out of the plate and replaced them with longer 3/8" bolts double-nutted to the plate. The bolt heads provide some additional security against coming out of the rubber grommets. An alternative would be to bolt the later bearing and its rubber retainer to the tunnel by drilling bolt holes beside the tunnel and perhaps adding some reinforcement over the top of the tunnel and using nuts or having them welded to the reinforcement. There is enough room in the tunnel so no further tunnel surgery is necessary.
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George Downs Bartlesville, Oklahoma

You want a M41. There are two types of M41s based on which Overdrive that is on it- The D-type (which is the earlier type - id by the solenoid on the right side of the OD-found on earlier 1800 and 122 - not sure on the years, but used sometime upto 1968 ) and the J-type(like the one above - id by the solenoid on the left side - found on 1800, 140, 240 and 122(?)upto 1975). I would suggest a M41 with a J-type Overdrive. Parts are still available for the J-type, not so much for the D-type.

You can't install just the OD on a M40, and M41s ODs can't be switched between J-type and D-type. It's all about the main shaft of the tranny.

List of parts:

-M41/OD
-Bellhousing (you can use your present bellhousing)
-Tranny top cover(you can use your present top cover (if you want to use the long shifter), but you need to install a fourth gear lockout switch - used to engage the OD only when the tranny is in 4th gear)
-Fourth gear lockout switch (usually can use the one from the M41 you get)
-Driveshaft (I would suggest taking your driveshaft to driveshaft shop to be shortened - good time to get new U-joints and get it balanced - The driveshaft needs to be shortened 11.5 inches)
-Wiring(you need to wire up the OD - there are many ways to do it. I use a OD relay from 240 because I like the design of how it works - I can send more info if you're interested)
-Light (a light is good to tell you if you're in OD or not. There are many ways to get a light. I use a circuit to make the turn signal light in the dash as a dual purpose light (bright for the turn signal, and a dim for the OD). Stock OD lights would require drilling the dash - I can send more info if you're interested)

I can't think of anything else you would need, but I'm sure others can chime in.

I just installed one on my '66 P130. It's a very straight forward swap. I spend more time cleaning parts and setting up then installing it (but I didn't remove my bellhousing because it had a good clutch in it, but it's a good time to change the clutch too - I can direct you to a new clutch kit for about $140 shipped).



Paul