70 Camaro or Chevelle Muncie M-22 10L517781

[Ls6 Ragtop]

Jason,
Camaro trans. No Chevelles in 70 were produced with M22 except 454 cars which were all 26 spline input 32 spline output. I don't believe any 396 cars have been proven to get the M22 for Chevelle. If this is a 10 spline input and 27 output from this plant would make it Camaro.
If the original trans tag is there it should be 3968012 WM. Pretty unusual trans for sure. 70 LT1 Corvettes could have gotten this same trans with the same part # tag.
Chris