Over the counter replacement m-22

[DMiller307]

Could an m20 have been replaced with an over the counter m-22 in late 68?

[MO]

Yes. It was an option in 1968, so it was available. 

[william]

It was an option for L78 & Z28.

[bcmiller]

Could an m20 have been replaced with an over the counter m-22 in late 68?

Yes.

[DMiller307]

Hmmm.  Not service replaced over the counter on a 350 l48?

[MO]

Very doubtful unless someone knew someone that knew someone.

[Stingr69]

Yes it is possible.  Either a warranty replacement or a parts department over the counter purchase.

They would have a "CT" stamping. 

[william]

A failure under warranty requiring replacement would be serviced with another M20.

[GMAD_Van Nuys]

Motor Trend article on Muncie transmission date codes:

https://www.motortrend.com/how-to/1607-how-to-identify-a-muncie-four-speed-build-date-codes-vins-and-input-shaft/

[bcmiller]

Service replacement under warranty is a completely different thing than buying a transmission outright over the counter.