3 Speed on the Tree

[Rufton]

I'm looking for ebay maintenance/repair/service manual title that covers SM318 and SM326 3 speed on the tree shift transmissions. I have X-6023 gmc trucks maintenance manual for 1000-5000 but the transmissin section is missing.

I think SM318 was used from 1955 til roughly 1968?
Not sure years SM326 was produced?
I think non-sync 3 spd SM318 is Muncie but some say it's Saginaw?
Is snyc 3 spd SM326 Saginaw?

I have long tail piece non-syncronized 3 speed SM318. 21.5" long from mounting flange to rear of tail piece seal.. Tail is 14 3/8" w/o seal. Case is 7 1/16". 4 bolt cover. Input = 10 spline 1.1" OD. Output = 27 spline 1.175" OD. Pilot = 0.6".

I am also looking for SM318 and SM326 specs. Not sure if SM326 is close to 21.5" long? Not sure if SM318 column shift linkage will work w/ SM326 w/ simple linkage mods?

[Rufton]

Curious about decoding also.

Wonder if "L 22 4" stands for casting date of 12-22-1964?

Any sources for parts, bearings, gaskets would be very helpful.

[Rufton]

Per ebay vendor: "Rebuild Kit for a GMC or Chevy with the 3 Speed Muncie 318 Light Duty Transmission for years 1954-69.You can identify this transmission by its 4 bolt side cover. This is a rear wheel drive 3 speed transmission"

Apparently the SM318 has no front seal; unlike F*rd. At least the one I have has no front seal. I didn't see front seal in rebuild kit pics either.