Calculators.. I have 235 75 15 on the rear and can go as fast as I want and still not exceed 2000 rpm. I live in flat land Indiana and it works well here. But I go to Virginia it does ok on interstate still ok but on back roads sometimes it requires some shifting downshifting to 4th. Around town, it will keep up with all but the boy racers at stoplight drag. BTW it is a 273 gear.
