I would have a final drive ratio of 1.904 and it is not much more than a 2.20 for steady speed cruising and I would have a better take off gear. With a 27 inch tire it would do 2000 right at 80 mph. I am planning to move out west with even higher speed limits so I think this should work out fine.

Just for fun I figured a 2.20 and OD would make a 1.52 final drive ratio and put 2000 right at 100 mph

I agree the roller cam would probably get a couple more hp because of friction loss but a flat tappet can get more lift at those real short duration numbers. I think with the magnums 1.6 or mabey even some 1.7 rockers and a custom short duration cam I could still open the valves a good amount to get some more tq.