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Transmissions and Rear Ends Three on the tree or four in the floor? Shift it all here.

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  #1  
Old October 3rd, 2020, 11:52 PM
Onthefly Onthefly is offline
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Default Transmission identification

so now that the motor is running strong my next step is the transmission. Just trying to see exactly what I have before I drop it and replace the clutch. Any help would be great!!! Attached picture of drivers side serial numbers, maybe you guys can school me in deciphering these.
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  #2  
Old October 4th, 2020, 10:40 AM
George Bongert George Bongert is offline
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Default Re: Transmission identification

Greetings Onthefly!

Those numbers mean nothing to me. Does your Transmission have a shift lever on the top, or two short shift levers on the drivers side of the Transmission? Shift lever on top, you have an SM420 4 Speed Transmission. Two short shift levers on the side, you have an SM318 3 Speed Three On The Tree column shift Transmission.
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Old October 4th, 2020, 03:45 PM
Onthefly Onthefly is offline
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Default Re: Transmission identification

Thanks for the reply!!! The shifter is on top, I know its a sm420 more trying to find the manufacture date. My truck was origi ally a Yakima school district truck and I *** I me had a 3 on the tree originally , it still has the steering column for that anyway. At some point a 4 speed was put in and I'm trying to keep everything as original as possible at least year wise.
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Old October 4th, 2020, 05:35 PM
BillT BillT is offline
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Default Re: Transmission identification

If it's an SM 420 for sure, the Date Code reads April, 22, 1958 (possibly 1948 if they made them that early, or 1968 if they made them that late).

Also curious. If it got changed from a 3-Speed to a Truck 4-Speed, did they change the Floor Hump or does it still have a Low Hump?
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