in response to a message on the NCRS # 12671
.? Mid weird 63-67 Heater Box interchangeability

Monday, 13 March 2001

63A v. 63B v. 64-67 cockpit heater boxes
Sir, The 63 had at least 2 cockpit heater box designs that I know of. They are stamped 63A or 63B near the resistor mounted on the steel cover plate. Both A and B used a differently designed stamped steel mechanism to control the defroster door (ala Rube Goldberg). The 64-67 models have a simpler designed mechanism (ala Hi Tech). The end of the main box where the inverted Y duct attaches is also slightly different on 63 and 64-67. Furthermore, the earlier 63A models have an additional auxiliary duct that mount above the inverted Y duct on the driver’s side. Consequently this end of the main heater box also has an extra rectangular cut out to feed airflow to this auxiliary duct. This 63 only early duct is rectangular, about 3” by 2” by 5” long with one end angled slightly. Would these 63 inner boxes work on a 64-67? As Joe said – yes. Will the judges know? If they are well versed and look into this area with dental mirrors – yes. Could you fool me? No, but I have never judged any Corvettes at any event.