I take back what I said earlier, I have the K-Factory front steering knuckles. With the weight of Lipos you can get lots of alloy goodies and not worry about being too fat. The 1.5 rear hubs are a good tuning tool as are the front C-Hubs in different degrees.

I have the one-way/spool which I used in 13.5 and mod on the asphalt. I swithed to the E4 front ball diff (35 tooth) for indoor carpet. I feel that a diff, especially in stock/17.5, gives better control and power in the turns where the track is tighter and more technical. The one-way is also good on a carpet track but is better if the track is more sweeping. The Track is about 50/50 so you could go either with a diff or the one-way, however, you lose front wheel braking with the one-way.