Diff breathers should be alot higher than that so you should be ok. If you are really unsure undo the drain plug in the diff and have a look at the oil for water, The screws your talking about sound like "plugs" They puch them in one way in the hope that they never will need to be refitted cause after ripping of your airdam you will go and by an aftermarket bar. Give it a good yank and if they break (they most likely will) then scoot off to DC and get some new ones. They will only be about $15 each.
