GMC decodes a little differnt than the chevy VINs do. I-1001-P-F6115A is the VIN you gave, which is as follows. I= inline engine, 10= model 1000, 01= 115" wheelbase, P= Pontiac Michigan assembly plant, F= series letter for 1964-1966, 6115= serial number, A= gross vehicle weight (GVW) 6000 lbs or less. Hope this helps