Flat side/raised crushable side ..... So which way ? ... or does it not matter 20 different answers on the interweb ... well 3 anyway
I normally put the cupped side to the block with the flat side on the back of the bolt I mainly use a lot of copper crush washer's, but they're just flat washers
Yea I use the copper ones also at times ... these are replacement plugs on the Cruiser diffs as the stock ones are junk after 20+years .... their photo has them that way and they were packaged that way also ... seems the logical way to me also http://absolute-wits-end.com/oem-magnetic-differential-plug-kit/