In Vietnam in '67-'68 we were getting both. So, in Korea there would still be "K" rations used.
The "C" rations were much better though.
Phormer Phantom Phixer
On the bench
TF-102A Delta Dagger, 32nd FIS, 54-1370, 1/48 scale. Monogram Pro Modeler with C&H conversion.
Revell F-4E Phantom II 33rd TFW, 58th TFS, 69-260, 1/32 scale.
Tamiya F-4D Phantom II, 13th TFS, 66-8711, 1/32 scale. F-4 Phantom Group Build.