[Cruisin428]

You should tell us how the car drives now, before asking if you should change something!

How well does it launch now? Changing gears means shifting faster. Smoking tires is smoking tires, making it easier to do may not add anything to the joy of driving it!

Do you find when cruising that one gear has too high of revs and the next to low so changing ratios may move to a nice in between?
When you are in"fun mode" how many gears do you go through before you get traction?
Also the posi will help with launch and traction so consider that before changing ratios.
As stated above, Look up how to calc the rpms and mph for each gear or use one of the online calculators for both ratios. That way you will be able to judge where you will move the mph and rpms to!