Sorry, I know of no one in Oklahoma racing 8th scale nitros untill spring. There are several tracks around where you'll be able to race once the weather warms up.

Here's a nice big nitro track on the west side of OKC.
http://www.oklahomanitroclub.com/

A nice track up in Witchita KS
http://emeryparkrc.yolasite.com/

And here's a place just east of Tulsa with 2 indoor tracks in case you've got an electric toy to play indoors with over the winter.
http://www.adamscreekrc.net/forums/

Hope that helps some. I know how you feel. I've been going out of state to race my 5th scale. None of the offroad tracks will let me run it.