I use aluminum tape to do the same thing on mine. Not sure where it can be bought (I get it from work) - but that stuff works great in certain applications like this.
Losi 8T 1.0, Savage Flux - XL style, LST XXL, Muggy, 3.3 E-Revo Conversion and sitting outside 425hp, 831 Tq Dodge Ram Turbo Diesel. It SMOKES