Proline does still make an inboard 12mm hub kit: http://prolineracing.com/performance...t-inboard-hub/

And if you have a 4x4 SC10 or a SC10RS, then you don't need to do any conversion to run 12mm hex wheels... those 2 models come stock with hex hubs. The Factory Team kit however, comes with pin and bearing style wheels. So if you want to run hex wheels on that model you will need to do the conversion on the front and rear in order to run Proline hex wheels. However, there are many companies that make conversion parts (Proline, JConcepts, AE, etc.) so, you don't have to run the Proline conversion kit in order to run Proline wheels necessarily.