My Challenger, when I got it, was 318/3.23/auto with smallish tires and most likely stock converter. It worked fine on the highway... 3.23 with a tight converter (bigger diameter as posted above) should work fine with a stroker also. I don't know how aggressive your cam is... that matters a lot for stall and acceleration but 3.23's, big tire and tight converter should work fine on the highway.