Filler Neck Conversion for AST Removal on RX-7 FD

Description

If your looking to delete the factory AST (Air Separator Tank) from the cooling system of your FD3s then this is the part for you. This is a genuine Mazda part that simply replaces the stock filler neck with two bolts. It is worth noting this this part is only compatible with certain filler necks (those that have a removable top section) You may also need the “O” ring if your original is not in great shape. The seals are sold separately. This part is now no longer available from Mazda UK or Europe, but we are able to source them from Japan directly.