R 1975 Y June, which is unusual as it has the steel dash not the later plastic dash which is in most 75's, 73/74 had the steel dash,
Sido number on the ID plate should be 73613 F250A 4WD C.Cab 3379 mm W/B 3493 kg GVM Cab chassis or 73614 F250A 4WD style side box 3379 mm W/B 3493 kg GVM
#did read a f truck forum post that said the F250 4x4's came from canada which is why the dash is different for a 75,
open chamber heads have 2 low bits with once being longer then the other, Closed chamber has 3 low bits about same size,