how much difference between 3.91 and 4.10

Hey guys,

I am building my scamp with a 340 as a daily driver...it will have a 727 behind it with something along the lines of 3000-3500 stall....I know its not practical for the road, but its the way im going to go...my question is for gear sizes....i plan on running a 325/50/15 MT street radial and i want to run either a 3.91 or 4.10 gear... i know neither will be pretty on the higway, but i dont take the highway that much anyways...i hear there is only a 5% difference between the two ratios, so my question is how big of a difference will i see between the two? how much higher would my rpms at cruising be with 4.10's compared to 3.91's?