Originally Posted by tclederman
I usually just link to the Novak Transmission SM420 page
http://www.novak-adapt.com/knowledge/transmissions/manual/sm420

but, here is ID info from Novak:

1947-1953:
No ribs on the case
Grooved worm on the input shaft instead of neoprene seal
Synchro rings all differ from each other. 1st-2nd synchro ring is bronze
Weep hole at 6 o'clock on the bearing retainer snout
Six digit casting number on the case, usually like "59xxxx" e.g., 591665

1954-1963:
Same as previous but uses a neoprene input oil seal
No weep hole at 6 o'clock on the bearing retainer snout

1964-1967: Same as previous except
1st-2nd synchro ring is aluminum and 3rd-4th synchro rings are identical to each other
Seven digit casting number usually like "37xxxxx", "38xxxxx" or "39xxxxx"

1968-1981: Military Con-Diesel version. Features the strongest case and optimized internals. Usually equipped with unique top cover, but can be converted to standard top-shift control.

590474 = 59xxxx = 1947-1953

My guesses are that the "1s" in the following code contains the year in a date:
F 16 1 = May, 16th 1951
B 17 1 = February 17th 1951

Let's try one thing at a time:
What is your engine serial number?
What are the other casting codes shown on this page:
http://www.1954advance-design.com/Web%20images/casting-code-photos/low-press-codes-ser-nums.html

What are you trying to ID?
- "rolling chassis" : cab? frame? drive-train parts?
- engine?
- transmission & rear end?

From a pervious thread of mine I was told the engine is:

Serial number 0146590F54XB breaks down as follows...

0146590 = Unit number starting with 0001001
F = Flint Plant
54 = Year
X = 235
B = 3800 Series Truck

I want to know what year the rolling chassis is.

What I do know is that I saw was the previous owners AD body being mounted on a S-10 chassis
at a body shop. Outside the building was the rolling chassis the engine was on the ground next to
the chassis (it was never attached).

He said the chassis was a 1945. The engine was a 1953. If he was wrong about the engine
year he could be wrong about the chassis year. Specially if that AD body that was in
the body shop came off of that chassis.

The transmission and the rear end and torque tube look original to the chassis.
So I am trying to date the chassis to the transmission and or rear housing.

So could my chassis be a 1951 based on the B 17 1?

Thanks Jeffrey