can someone please decode these parts as to the year

the main case has 3851325 no rings on input shaft
on the top of the case it has 313532 on one side and 51132532 on the other.. towards the back where the tail housing bolts up has P202

the side cover has 3831707 and the tail housing has 3857584. Thanks

Look for stamped numbers and letters on a flange where the main case meets the tail case.

The casting numbers say it is a late 1965 Muncie.
P202 says it was built Feb 02.
That is about all the information available from these numbers.

Since you guys are on the subject! I recently purchased what I believe to be a 69 muncie m-20 and need some help to determine what it was originally installed in. I'm new at trying to identify muncie's so if I miss some number let me know.

(P9E14A) P=Muncie 9= 1969? E=April 14= day A=M20 RATIO
Main housing cast# is 3925660 68-70 M-20
Tail Cast# 3857584 66-70 pass side speedo 27 spline output 10 spline input
Side cover cast#3952648 short boss bolt on type shift levers

I think the above numbers I have figured out correctly?
This is what I need help with. There is a side tag that is stamped (3946797)
I cannot find any clear evidence of what it identifies. I have seen things on the net like 69 camaro ,chevelle, impala but nothing clear. Will this tag not positively ID it to a certain Model? Also, I did find what I think is a partial Vin?
That # is 19W504806. I think this trans is pretty much all original . I know some of its history from the previous owner and sounds like it was in storage a very long time. Looking back he could not tell me what it came from for sure owning many 60s-70s GM muscle cars.

Thanks in advance.:bowtie:

Also, I did find what I think is a partial Vin?
That # is 19W504806. I think this trans is pretty much all original . I know some of its history from the previous owner and sounds like it was in storage a very long time. Looking back he could not tell me what it came from for sure owning many 60s-70s GM muscle cars.

Thanks in advance.:bowtie:

Colvin's book says that the W in the VIN means the car was built at Willow Run. He also says that Willow Run built only Chevy II cars in 1969, so that pretty much narrows it down to a Nova, and a Muncie in a 69 Nova would have come out of a SS Nova.

Colvin's book says that the W in the VIN means the car was built at Willow Run. He also says that Willow Run built only Chevy II cars in 1969, so that pretty much narrows it down to a Nova, and a Muncie in a 69 Nova would have come out of a SS Nova.
The "1" in the partial VIN further identifies it as Chevrolet which would support your ChevyII theory. the only hitch I see is that the Chevy II VINs start at 300001, so with a number of 504806 that would make it the 204,805th off the line...that seems pretty high for an April to early May car (basing that on the build date of the tranny and that it most likely did not sit around for a long time) - how many Chevy II's did they build in '69?

I was able to find that 251,849 Novas were made in 1969, so 204,805 does seem high for April-May.
And, I believe that there were more than one plant producing Novas that year. If so, no car would have been the 204,805th VIN.
So, there is a possibility that the VIN numbering didn't actually start at 300,001 as Colvin's book indicates.

Wow guys , thanks for the quick responce ! So if I understand what your saying on the partial vin the first digit is the Division of GM and 1=Chevrolet and the numbers from that point on are the last part of the vehicle's VIN.


Is it possible the steel tag on the side cover may represent the engine type it was mounted to ? I did look into the different Nova SS engine options for 1969 and It looks like there are 3 of them a 350 and 2 different 396's

Look on the passenger side (fill/ drain plug side)
Where the midplate meets the case
and look for a set of numbers
first digit should start with a "P"
the last letter designates the gear ratio

Look on the passenger side (fill/ drain plug side)
Where the midplate meets the case
and look for a set of numbers
first digit should start with a "P"
the last letter designates the gear ratio
Buckeye has already provided that info.

80RS's tranny is way too early to contain that sort of info in the build date stamp (which he has also provided).