R7 OD in a 50 Plymouth with a 251 Flathead

[50Gravesend]

I have a 1950 Plymouth Deluxe that I dropped a 251 flathead six into from a 1952 DeSoto. I used the 1950 bell housing, clutch setup and the stock 3 speed manual transmission as it bolted right up and its what I had. I have a chance to buy an R7 overdrive and I need to know if it'll be a bolt for bolt swap. What will I need to make it work properly? Is there a specific model number that I need? I know the R-7 was made for other vehicles but I have no idea which one would fit my 50 Plymouth. I've done some research but the more information I have the better I'll feel about driving 600 miles to get that R7. Thanks in advance.

[Powerhouse]

R6s were for 37/38 chrysler /desoto 6cyl I believe.  Non electric and floor shift.

Edited February 25, 2014 by Powerhouse

[Don Coatney]

What flywheel did you use?

 

Not sure where in Pennsylvania you are located but you might want to call George Asche in Venus, PA as he is an overdrive guru. His number can be found in the Links section of this webpage. He does not do the interweb.

[builtfercomfort]

R7 was also in the 39 Chrysler (and maybe later?) with column shift. I am not sure if that column shift is like later ones or not. I heard a rumor that you could swap the top of a 39 trans with a 38 trans top to get a floor shift but that's unconfirmed.

[Dodgeb4ya]

The R7 is column shift OD trans that was used in the 1939-40 chrysler six and Eight cylinder cars- 1941 chrysler eights too but hooked up to the vacamatic trans.Also same as used in the 1939-40 DeSotos .

I once put an R7 in my 1951 cranbrook and it worked just fine. As I recall I had to swap the rear U-joint flange and wire it up so it would kick down on forced down shifts. It was a bolt in-just make sure the input shaft bushing area is the same position and diameter!

[meadowbrook]

I bought an R7 from Asche and it was a direct bolt on to my 1950 Meadowbrook. The only required change was a longer speedo cable. Sure, it's all mechanical aside from the kick down solenoid and relay (unlike the R10, the solenoid is only activated during the kick down), but that's why I like it. Works like a charm and I get 22 mpg if I drive around 50 in od mode.

[Alshere59]

I'm running an R7 in my 50 Plymouth and love it. The only thing to add is you may need the shifter arms off of your current 3 speed.