technically the way Tim puts it is the way GM designed the CDN numbering system, but it works grouping the numbers - 13 = the series [1/2T Chev, 93 is 1/2T GMC], and 14 = the model [short WB pu, GMC or Chev, 24 is the long WB pu] - the question is with the actual sequence# as they always started with a certain number, like 10001, so it would prolly be the 5,348th truck produced rather than 15,000
Bill