Muncie dating.

[Flowjoe]

hello, I'd like to pick your brains.  a friend emailed me a picture of a  muncie he picked up with a 660 case & a 584 tail shaft.  The assmebly date stamp shows a P0P03...that would make it a 1970 model year correct?  but a 660 case should be a '69 model year application.  And the date seems odd with the P03..any thoughts?

[RAfbody]

It looks like a very early transmission for the 1970 model year.  There should be a partial vin stamped on the transmission as well and there should be a letter stamped at the end of that date (A, B or C).

[JohnZ]

660 cases were used in '68-'69, and only 4 digits after the "P" says it's a bogus stamp for a 1970 usage; Muncies built after October, 1968 had a ratio designator as the sixth character.

[Flowjoe]

Thanks guys...It has a ratio designator....I just didn't include it as I was more interested in the "P" month code and the model year '70 on what should be a 68-69 case...there is no VIN but I went back after posting (but before reading your responses)and noticed that it has CTO stamped near the build date...John:  Would that stand for Chevrolet Transmission, as in replacement tranny?

So i solved the "P" month code...i forgot Muncie didn't follow the straight linear progression of Alpha character to Month formula..."P" = September...my error.

So now all I am still confounded by is the use of the earlier case (660) with a model year '70 build.  Perhaps replacement trannies would have something like that? 

[JohnZ]

Yup, "CT0" makes it a 5/50 warranty replacement service transmission, built in 1970. 

[Flowjoe]

Thanks John, you're the best..i really mean that.    One follow up quesion...I know 69 produciton 660 cases did not receive a drain plug but that all 661 cases in 70 up did.  since this is a 70 built 660 would it have been normal proceedure to drill and tap for a drain plug?  thanks again


Joe

[JohnZ]

It's hard to tell what detail specs were followed at Muncie for service replacement transmissions - don't have an answer for that one.

[Flowjoe]

thanks anyway John...this one is drilled and tapped so that picqued my interest enough to ask the question