I have been having some trouble figuring out what engine is in my car (A base model 1969 Camaro that originally had a V8). I was told that it was a 350ci engine that isn't original to the car. From what I can tell, the engine is either out of a 1978 Corvette or A-body car, although I have been told differently. Here is all the numbers I could find on the engine:

Engine ID: 404633 K09 17 CMR

Casting code: 3970010

The closest thing I can find to a date code is K 10. The number is located where the date code is supposed to be, and K 10 is all that is shown there. Any ideas on what this engine actually is? Thanks!