I put mine about 2" up as well, since it made for a nice formed diptube length. The problem I have is that using the Bargain Fittings sightglass, 5 gallons doesn't even show in the glass. My sightglasses are for 10 gallon batches only. This hasn't ruined any beer, but I was hoping to be able to use the sight glasses, but to get any volume accurately, I need to measuring cup it.
The moral, if you are ever going to share the bulkhead with a sightglass, put it as low in the kettle as humanly possible.