Engine Code For 1970 Super Rat

[Joe Ormonde]

Does anyone know the Beginning Engine Number for a 1970 Super rat? 1969 starts with M1001 and 1971 starts with M5750, but where does 1969 end and 1970 start? 1971 is simple because it starts with M5750 and 1972 starts with M12434 so anything in between is 1971. I`m building a 1970 Super Rat and the Cases are in the High 4000 range so I`m good to go. So, 1970 Beginning Engine Number. Does anyone know it? Joe Ormonde.