Are you talking Chev or GMC? GMC 1/2 tons came with either 114 or 123 1/4 Wheelbase. 3/4 ton came with 123 1/4 wheelbase only. 1 ton came with a choice of 114, 123 1/4 or 135 wheel base. Chev had only the short wheel base on their half tons through early 55. I don't know much about Chev 55 and later.