[Synchro909]

Tomscott, what year is your car? If it has 21 inch wheels, you can get the same overall gearing by fitting 5.25X21 tyres - about 5% higher. They are 6 ply rated so the walls are thicker and they are more stable in say, a cross wind. A pair of tyres will be cheaper than a new set of gears apart from all the extra work and if you don't like the higher gearing, changing back is easy. There will be someone willing to buy your 5,25 tyres.
All of that said, A Tudor is not the lightest Model A body so you will really notice the difference unless your engine is above original specs. IMO, a 6:1 head and a bigger carburettor is enough to get the extra oomph you will need. A hotter cam comes next.

Pete, with respect, I cannot possibly agree with a Model A doing 65 all day - certainly not if you want the middle main bearing to survive the trip. For a long engine life, not much over 40 mph is all it is good for. Don't ask how I know!