I took out the cups on an old bike I was working on (a 1989 specialized stumpjumper comp). The spindle was shot but the cups are good. When I threaded the fixed cup, I noticed that it was tight on one side and not flush on the other. The gap is right around 1.5 mm. I don't believe that the BB shell is cross threaded as the threads look fine on the fixed cup and it threaded in easily enough (I needed a tool to turn it in parts as the fitting is a little tight but this did not require any force). It certainly is tight for the last few turns but there is paint in the shell so I'm not surprised. I'm guessing that this is the way the BB shell came straight from the factory.

I know cup and cone takes a fair amount of misalignment but is 1.5 mm something to be concerned about? I'd rather not pay to have the BB shell faced. This is just a commuter bike but one I really like so I'd consider getting some work done on it. It bugs me that the cup is that far out on one side, however. Should I get the shell faced and the threads chased?