Absolutely run 6.5 qts. If you get it too full you end up bathing the rank and losing power/foaming the oil, but that happens somewhere north of 7.0 qts. 6.5 is good for the street, when racing I run 7qts, without problems.

-Philip Maynard '95 Contour [71 STS | Track Whore] '97 Miata [71 ES | Boulevard Pimp] 2006 autocross results