engine stamping

[CUDA71383]

Can some one help decode this engine stamp?

 

[CUDA71383]

not sure what the r means?

 

[challenger6pak]

October 17 (E) 1970 383. It would be built for the 71 auto production. Is it the original engine to your car?

 

[challenger6pak]

IIRC R meant regular fuel, as in non high test.

 

[CUDA71383]

no a guy gave it too me so im going to put it in my 71 auto cuda he also gave me a seized 67 440 that I don't need its seized due to being in the back yard for years