Can someone give me the info off this muncie?

The front casting #3925660 , tail casting #3857584
Stamped #'s: P9M24 and 42773

Thanks-

"P9M24"= P=Muncie 4 speed pass. car except corvair, 9=1969, M=August, 24=24th day.
3925660 and 3857584 are casting numbers that are consistent with different Muncie tansmissions. The 42773 could be a partial VIN. Looks like it could be an M-22 but I am not certain.

It should have another letter after the 24 in the stamp code. The 69 model year is when the stamp included a letter code. A = M20, B = M21, C = M22. The 42773 does look like part of the partial vin. Take another look and see if there are more numbers and letters.

I cannot see any other letter after the 24 in the stamp code... If this is true about the 69 having a letter after, what does it mean if there isnt one?

Also ..I suspect it to be an M21, but how can i tell if it is an M22?

Your trans was built Aug. of 1968 for a 1969 model year car,,, the A-B-C coding didn't start until the end of Oct. of 1968, that why your's doesn't have it...
Partial VIN's are 6 digits, and by 1969 model year they included GM family code,,,
1-----------Chevy
2-----------Pontiac
3-----------Olds
4-----------Buick
Model year of car,,,
8------------1968
9------------1969
0------------1970
and so on,,,
Plant designation,,,
N------------Norwood
W-----------Willow Run
L------------Los Angeles
And then the 6 sequencial VIN...
So 19N999999, would be a 1969 Camaro built at Norwood
And 29N999999, would be a 1969 Firebird

The 42773 could be the serial number for a complete trans assembly sold over the parts counter...
Hope this helps... Crash