Crankshaft Oil Slinger is it a must or not???

Those things seem to grow legs ! I had about three of them sitting around my garage in various boxes.Went to assemble my short block and couldn't find a single one of them !

Hell, that's like everything at my house. Parts, tools, jigs, books, instructions, paperwork, titles, you name it. Guarantee as soon as you buy a replacement, or don't need it anymore, it will turn up along with another one you forgot you even had.