transmission ID

[bigred1]

I have a 1963 gmc 1500 4 speed manual, where is the ID number for the transmission?

[Funky61]

Check Drivers-side upper area, under the grease.

Do you have any photos of it and where is reverse location on your shifter?

How can you tell which 4-speed your 1966 has, if reverse is to the
driver & down, it's the SM-420, if to the passenger & down, it's the NP-435-GA


Jolly Page:

https://6066gmcguy.com/SM420.html