Billet aluminium pullies, for the water pump, and crankshaft. Both the smaller OD Fairmont fan/water pump as described in the "Cooling the Sunbeam Tiger" paper, and the stock OD
https://rstech.my-online.store/browse/catwcE2b_716337.aspx
https://rstech.my-online.store/browse/catwcE2b_716337.aspx