Vintage Air Sure Fit air conditioning, heating and defrost systems are designed to be used as a direct replacement of your stock OEM heater or warn out air conditioning system in your 64-65 Chevelle. It matches the coil and blower to give you the maximum amount of comfort in your vehicle. Factory controls are used with these systems. Sure Fit evaporator packages install without drilling extra holes, providing your car has a stock dash and firewall. Some of the features of the Sure Fit system is that it mounts completely behind dash,  has a center molded plenum and two remote ducts for maximum air flow, and it has a high capacity blower.