i also run on clay and sometimes dusty or damp if not swept well between heats,
the jconcepts were great when new but if i dont keep them clean they work ok and seem to wear quickly. the prolines work good too and seem not to wear as quickly as the the goosbumps but also need to be cleaned to make them perform well. get a better foam for both as that helps alot i have the 2 stage (i think proline makes it) in both and seem good , i also tryed 1/8 buggy foam that also works well . i use the gt rear hubs and needed to order a new outside bearing , and cvd . i heard the 1 degree work but i thought the sc10 came with the 1 degree hubs already. i also found 1+degree (not negitive) in the rear chamber makes it go straiter , you may want to try that before ordering the hubs