Mike, what is the recommended time frame for recharging the 15" cone we installed? It turned to a grayish color after a few hundred miles. Do you sell the oil/kit for it? Also, did you receive my past couple emails (to your TroyerPerformance address?) Truck's running well (12.5 at 109 1.84 60' on 93 gas, street chip, Drag radials and full weight last week, John.