Aluminum S5 Thermostat Neck/Elbow 1989-1992 RX-7Aluminum S5 Thermostat Neck Elbow Finishes Available: Polished, Bead Blasted, or Black E Coated Application: 1989 1992 MAZDA RX 7, aka S5 Models Rotary13B1 has made a thermostat neck in Aluminum to replace the brittle, often cracked S5 unit. Get one of these when you change out your thermostat. These are made directly using an OEM piece, direct copy, but in aluminum. We have them finished in highly polished, bead blasted, or E Coated black for that