Yes a more usable RPM. with my gear as of now 3:91 & my 4-speed it hits the Rev Limiter very fast and it breaks the tires loose so i am spinning & shifting and it keeps spinning & hitting the Rev Limiter i am getting ready to put a taller rear tire from a 27/10.5/15 ET streets to a 275/60/15 drag radials out back which i read is 1" taller i think.
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You say that you want more rpm, I presume that you mean more usable rpm between your cruise speed and the rev limiter.
Gear choice when balancing crusing against best performance/fun factor, is usally a compromise and boils down to an individuals preference. Do the math as Mr.P suggests, or use an on line calculator to see how the rpm will change with different axle ratios. Also, if the concern is simply bumping into the rev limiter, maybe move it up a few hundred rpm. I would think that you would be shifting around 6000 anyways, and a 600 hp motor should have the internals to safely rev past that. 
