RPM issue?

Hiya wondering if hitting 6300 rpms at 65mph is all I can expect on my setup. I just recently got new tires and wheels, and I know I’m going to suffer some issues but dang it, I wanted DOT tires.
Oh well, overall I’m not mad by any stretch, just wondering if there is anything worth doing different. I’m just concerned about RPM’s when I get onto sand. Granted these tires aren’t going to be optimal, but I’d like the most rotation as possible.
Non-cosmetic Mods listed below and a link to a youtube vid of my tach/speedo

Grumpy air intake mod
SLP Super Silent Muffler
EPI Dune clutch
Carbon fiber belt
14" Beadlocks
EFX Motohammers 27x9x14 and 27x12x14
Just tightened throttle cable