Help With Muncie Transmission Case?

[Don L.]

Can someone - anyone - decode the braille markings on this M20 transmission casting? FWIW, the casting number is 3925661.

Thanks in advance for any help.

[David L.]

Re: Help With Muncie Transmission Case?

Don,
My educated guess is the case was cast during the 4th week of June. I do not think the large number "9" represents 1969.
What is the stamped code just to the left? (example: "P0K20A")
I have an original 1970 Corvette Muncie 4-speed transmission (casting # 3925661) stored in a box in my garage that I bought at a swap meet in Connecticut about 30 or more years ago. I will have to check out the stampings on it but the date code on it is 1970 something. I actually bought it for my long time 1970 Camaro SS350 project which is no longer a project any more.
Dave

[David K.]

Re: Help With Muncie Transmission Case?

Contact John Perrette, his info is on the inside front cover of the Restorer.

[David H.]

Re: Help With Muncie Transmission Case?

Can someone - anyone - decode the braille markings on this M20 transmission casting? FWIW, the casting number is 3925661.

Thanks in advance for any help.

Don

I also believe that date code would indicate 4th week of June. Extract from link below on "Chevy DIY" web page. Each section representing a month, with each raised dot representing a week.

....

https://www.chevydiy.com/muncie-4-speed-identification-guide/

Dave

[Don L.]

Re: Help With Muncie Transmission Case?

Thanks guys. For me, it's one of those things where I have little left to do on this car and I'm digging in to the trivial items , mostly trying to learn.

I purposely didn't post the date stamp for the transmission in my first post, not wanting to lead anyone astray because of the quality of my stamp photo. I can't get my camera in between the tunnel and the case and still get a clear focus. I have attached my best shot of it it here. I redacted my VIN. I'm pretty sure my date stamp says P2M09A, which I believe correlates to Muncie / August 9 / M20. Coincidentally, this date matches engine assy. on my car to the very day.

So, does a 4th week in June casting make sense for an August 9 assembly date? Seems logical but I don't have the collective knowledge of this group. Also, it seems years are not accounted for in either the casting date markings or the date stamp from assembly operation. Interesting.

Mainly, I was trying to decode the dimples. I was on the wrong track, thinking it was a month/day/year code. Thanks to this group, I now get it.

Thanks so much!

[David L.]

Re: Help With Muncie Transmission Case?

Don,
The "P2M09A" would translate as Muncie, 1972, August 9th. The 4th week of June would be fine for a transmission assembly date. This was not like a super market where they rotate their stock.
Dave