Jared.. maybe somebody else knows for sure but I didn't see any washers or spacers on any of my 400's. I have three and have had the fenderpans off all of them. My manual doesn't show any either. Btw, you are not allowed to install Super Lugs unless you post pics. It's a much hallowed WFM rule and you would not be allowed to use the secret handshake anymore if you break it. If we had a secret handshake.
All my manual says on fenderdecks is this:
Army
All my manual says on fenderdecks is this:


Army