If you omit the spacer you need a bigger indent in the bottom collar so that it seats on the head instead of wobbling about on the valve guide which protrudes 9/16s of an inch if you read the drawing.

Hey Buddy! How are you? Nice to see you here. Have you had Covid shots?

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My WD G3L hasn't got one and it runs very well,it's absence can't do any harm so don't worry about it carry on.
Richard.

I think you're wrong Ken. The collars are the same for both valves and will drop down over the guides onto the head, however far the guides protrude. Ron

email (option): ronpier@talk21.com