4:11 ratio vs. 3:78

[1955cj5]

Through another thread on this site I learned that my differential ratio is 4:11. Remember I also have a 4-speed which does not really matter in high gear but may affect the lower gears.

I also learned that my speedometer is reading about 5 mph high, so when cruising happily at 40 I'm really doing 35. I think it's the driven gear but that is another story(number worn off the turtle)...when I indicate 45 or so it starts to sound a little over-worked. I have been as high as 50 indicated, but don't plan to do that again!

I found a complete rear end out of a 31 Tudor, torque tube, brakes wheels spring etc. Assuming it's a 3:78 would the different ratio make the truck any more drivable or would I hardly notice the difference? Would it be worth the effort? I have no plans for touring.

Would a 3:54 be too high and just create other problems?

Thanks,

Randy