i saw a 1978 ford van while garage saling in norman. mag wheels,351w, beautiful black paint job. i talked to the man for a minute. he's having trouble finding parts. its his lucky day. i been driving mine since 1980. i know know where to find parts. my fathers cattle hauler sits in my driveway. 1979 f250 from canada. how do i find out hom many were prduced with 4-door cab and 460 motor?