7 1/4 with 3:55's or even 3:23's

So how is a stock 225 with a 994 and 3:23 compared to 2:9/2.7 whatever rears? Assuming stick tire size.. is it that bad on the highway?
With stock height 13" tires, and three speed manual transmission, Vixen turns about 3100 at like 72 MPH. I normally drive her in the 2500-2800 range, though.