oil drain/fill/level screw replacements

[greggimlick]

I've got a 1988 Evinrude VRO 90hp outboards on a 16' McKee. I'd like to replace the screws for the drain and level in the bottom end. This is a used motor and boat and I had a heck of a time getting the old ones out to service the unit. They're okay, but I can see that over the years the slots have gotten boogered up so I'd like to get a new set if possible. I put new o-rings on the old ones and reinstalled them, but if I can find new ones I'll replace them next time.<br /><br />Any suggestions on using something to coat the threads to prevent corrosion and freezing up?