2.93:1 rear gears

I have 2.94's in my Swinger. I'm currently running a Mopar purple shaft. .484/.484 [email protected] in a Magnum 360. My car came with three on the tree, and now it's floor shifted.
My car is pretty fast, but could be faster. I'm going with more gear when I put either a TKO 5 speed or a T-56 six speed. I want to see where the rpms are in overdrive to help me decide what gears to put in. Hope this helps.

P.S. Like your cars color!