The ice cream truck is a 3112. Check out this thread:
http://forum.imcdb.org/forum_topic-862-Chevrolet_Truck_I_D___s_of_the_1940_s__1950_s.html


For the record, 1960 was the year Chevy started labeling their trucks "C-10," "K-10," "C-20," "K-20," "C-30," "K-30," etc.