Limited, WKA rules Limited flathead 325 lbs up to .080 over, WKA rules Animal 375 lbs, $500 purse. Open, WKA Open flathead rules, 14.5 cuin 325 lbs, OHV Open, 14.5 cuin 375 lbs $1000 purse $500 to win. Also running UAS race, not sure about the purse. See the track section for other classes.