Why eight washers in windage tray install kit P3690939?

Actually, the washers are for a 360 application. 318s and 340s came from the factory without washers, but the 360 uses the washers because with the longer stroke, the rods tend to clip the tray. The washers move the tray further away from the crank, eliminating the problem. I've only ever seen four washers in the kit, though.