COPO Nova Transmission

[STR8SS]

New member here.... just thought I would try and put a myth to bed.
I bought my Oshawa built L34 '69 Chevelle SS this past May... the PO told me that the M20 that is in the car now could have come from a '70 COPO Nova.
I read a while back that most of the '70 COPO Nova's were shipped to Yenko but 2 cars remained in Canada. I've also read that the '70 COPO Nova cars all had M21's???
Here is the info I have:

Casting: 3925661
Side Cover - 3952648
Tail Housing - 3857584
VIN - 10W199469
Date Code - POS24A

So it is an M20... with a Nov 24th build date which would make it for a 1971 model year...so that might shoot this myth down but I figured I'd give it a shot and ask you guys!

Thanks,
Chuck