Bix Stock class. Running two tx11 and two tx22. Squeals and scwals bad. We are not allowed to prep tires. I know they are too soft so how do I know what compound to use. Treaded tires are hard to come by here so I would like to get the right ones. I would think 33 or 44 but don't know which one. The track usually ends up with pretty good grip. Usually rough as hell. Any suggestions?