The head stud washers supplied by ARP in their Z32 300ZX head stud kits have a smaller Outside Diameter than the OEM washer. Common practice is to stack the ARP kit washer on top of the OEM washer to achieve proper load distribution.
Alternatively I offer these Heavy Duty washers from ARP that are the same Outside Diameter as the OEM Z32 300zx head bolt washer.
Ships as a set of washers.
Includes delivery to AUS.