I race the midsouth series, and you definately wouldn't want to be any wider that 46.5, or maybe 47 at the most for that series. The track/trails we race on are pretty narrow!!! The midsouth is definately the best series in the TN, AL area!
This other series in GA is suposed to be more wide open like gncc races. So you might be okay with a wider quad for that series. I would probably get in touch with the series promoter and see.
There's also a series in KY that is suposed to be pretty good.
I would suggest raiing your ride height over a MX setup to around 7inches for more clearance. And dont forget to run skid plates.