Canadian 251 flathead 6

I just bought a 251 flathead 6 that came out of a 1957 Fargo or Dodge 1/2 ton. The engine ID number is K18589C. It also came with a rebuild tag saying it was rebuilt in Winnipeg by the Chrysler method. In all my searching I haven't come across any engine numbers with a "K" prefix. Does anyone know what that K designation means? Could it be a designation given to factory rebuilt engines? I'd sure like to hear from someone who knows something about this. Thanks, Albert.

K - 1957 model year

Chrysler Engineering used letters for the model year = A, B, C, D, E, F, G, H, J, K, L, M, P, R, S, T, and V.

The first series started with 1924-25 and continued through to 1941. Second round started with 1942, had combined model years 1946-48 and 1951-51, and ended in 1964. The third round started in 1965 and ran through to 1980. The letter Q was used once - 1960 Valiant.

If it was rebuilt in Winnipeg it would have been done by Century Motors.

K18589C means it was the 17,589th 1957 6 cylinder engine built at the Chrysler of Canada engine plant. The first engine was K1001C.

K - 1957 model year

Chrysler Engineering used letters for the model year = A, B, C, D, E, F, G, H, J, K, L, M, P, R, S, T, and V.

The first series started with 1924-25 and continued through to 1941. Second round started with 1942, had combined model years 1946-48 and 1951-51, and ended in 1964. The third round started in 1965 and ran through to 1980. The letter Q was used once - 1960 Valiant.

If it was rebuilt in Winnipeg it would have been done by Century Motors.

K18589C means it was the 17,589th 1957 6 cylinder engine built at the Chrysler of Canada engine plant. The first engine was K1001C.

Thank you. As I was told the engine came out of a '57 1/2 ton, that confirms that it's actually a '57 engine.