Kohler - Spark Plug Chart
 

Here is a Kohler Spark Plug Chart for the K, KT, & M Series motors as used in Cub Cadets:

https://s25.postimg.cc/bknnvmzi7/Kohler_Spark_Chart.jpg

In addition, here is a chart for the Autolite brand of plugs suitable for the Kohler Motors:

https://s25.postimg.cc/pflye3txb/Autolite-_Koh_C.jpg

Thanks to Myron Bounds for research, input, and advice.