1The size of superior air conditioning bulkhead is 1 6( 5/8in18), heater port is 3 10(7/8in14). 2Manufactured by 6061T6 billet aluminum alloy with high reliability, have a longer using time. 3The bulkheads are suitable for all common OEM and aftermarket air conditioning and heater systems. 4A better replacement for Classic, for Hot Rod, and for GM Performance and for Ford vehicles. 5Exquisite production, with good performance and higher work efficiency, brings you more convenience. Item Type: A/C Bulkhead Material: 6061T6 Billet Aluminum Alloy Fitment:Compatible with all common OEM and aftermarket air conditioning and heater systems. Replacement for Hot Rod vehicles Replacement for GM Performance vehicles Replacement for Ford vehicles 1 xA/C Bulkhead