I looked at a few 660 muncie transmissons and was wondering why some of the 3925660 casting numbers on some are smaller and some are bigger from trans to trans.Is it because some were 68 trans and some were 69 trans. Does anyone know if there was a time period that these casting numbers changed?

There are a lot of different masters used in the casting process...
I've looked at all the different 660 cases I have (close to 100) and the same good and bad casting show up thru the hole run of 660 cases... Hope this helps... Crash

There are a lot of different masters used in the casting process...
I've looked at all the different 660 cases I have (close to 100) and the same good and bad casting show up thru the hole run of 660 cases... Hope this helps... Crash
Do you have a log of VIN stamps on those 100 cases, by chance?

Gary, Are you looking for a perticular assembly plant??? Crash

Gary, Are you looking for a perticular assembly plant??? Crash

No, just my original N613111

Gary, sent you an IM.

I'm looking for an 010 case and also some 69 shift arms

Gary, The closest I get is N598147...
Tom, What date are you looking for??? Crash

Thanks for checking! One day I may find mine.:hurray:

Crash, so your saying that the smaller,crisp numbers and the larger faint numbers change throughout the the 660 period from what you see when looking through your cases?

crash.. I'm looking for an 010 m21 with a mid sept to early oct date for an early 66 car

Tom, I have a P0930 complete M-21 core with a K-VIN...
I also have a P0902 re-bushed case only that can be built as an M-21 (has a goofy VIN on top)... Crash
crash_enterprises@yahoo.com

Luke, I looked at some of my cases and found several with the same master number, and compaired the cosmedic flaws(numbers,texture,ect.)... The same masters were used all 3 years of 660 production(1968-69 first half of 1970)... Hope this helps... Crash

Thanks for the input , might see you at spring Jefferson thanks,Luke