When does a Pickup become a " Historical Vehicle"?

In Kansas it has to be 35 years old to qualify. That body style Ford was built from 67 to 72 and I had a 72 F-250 camper special with a 390ci. The factory A/C was mounted under the dash. It had two fuel tanks (and needed them) one in the cab and another under the bed. It also had two sets of disc brake calibers on each front wheel with outstanding braking. The C-6 Transmission was rugged with a full floating limited slip rear end.