I have a 1962 Chevy c-10 with a 235 6 cylinder. The heater hoses were disconnected because the guy I bought it from said the core leaked. No problem just get a new core, well looking at the heater it does not resemble any in the shop manual nor does the core measurement match any replacement cores. The firewall has plates over the holes where a deluxe would fit one is square another is rectangular above and the fire wall cardboard inside has knock outs that have not been used.
Were trucks sold without heaters in 1962? Could this have been a aftermarket of some type? Would any heater from say 1960 to 1965 work in a 1962?

Any answers will help.

1962 Chevy C-10 Pickup Truck