New member, Gator 6x4 help

Hi, Just rescued a Gator 6x4 from the scrap yard. The serial number is W006x4x022818. Can anyone tell me the year model? The engine is a Kawasaki FD620D-CS11, ENo FD620D105444. Does this engine have the plastic cam gear? Also does anyone have a cross reference for the radiator cap so I can buy from an auto parts store?

Thanks for any help.