Depends on the intent. You can have the difference and use the home team's ballpark, during interleague, to determine which to use because of the DH rule. But that stat is about salary negotiations.
I think that either way, it should be 7 innings, and not 6 for a quality start. my reasoning is that 7 innings leads you into the fairly simple situation of Set-Up Man in the 8th, Closer in the 9th. which gives you the best chance to win.
