Shawn, there is a Woodbridge Kart Club road race this coming weekend at Summit Point Raceway, in Summit Point, WV. It will be on the Shenandoah circuit. There will be MANY shifters there and a few vendors/engine builders as well. You could bring your kart with you and have one of our shop guys look it over and get you headed in the right direction.
If you decide to attend and have a look around, look me up. Red trailer, white canopy, parked near the front, doing pre race safety tech.