5/8″ (16mm) HPS High Temperature Reinforced Silicone Coolant Cap. 5/8″ is the ideal size to block off heater hoses.
SILICONE COOLANT CAP, HEATER BYPASS 5/8″ (16mm) HPS
$21.74
Radiator Hose Set, 84-85, GSLSE 13B, Silicone
Radiator Cap Neck, 86-88, Without Over Flow Tube
Sorry, this item has been discontinued by Mazda.
You can use the radiator cap neck with over flow tube N326-15-17YA and cap the tube with a 8mm cap, which you can order here
Water Pump Housing Gasket, 74-85 To Engine
This item has been discontinued by Mazda
Plastic Push Button Type Rivet, 86-On
Lower Radiator Hose, 79-82
Water Pump Gasket, 04-08 RX8