The build date is 5-13 HP2 . It was hard to read in the garage which isn't very well lit, but the vehicle order number looks like 8b38042 . I am not sure about the 8B as they could be B8 or ?, but I am sure about the 38042! If you can prove it's your original motor, let's get it back into the car. Appears to have been rebuilt prior to me buying the car. It came in a 70 'Cuda that I got out of the Northern Illinois/Chicago area. pstewart7@att.net