The MGT spurs are supposedly easy to fit on the traxxas slipper, and are mod 1 and available in 46t.
My slicks are belted with duct tape, and really dont balloon at all. It was basically undrivable with unbelted tires.
Because of the maxx driveshafts Im running, the biggest spur I can use is a 44t. I run a 40t because the revo spurs are a direct fit, while the rs4 spurs take a lot of dremeling every time a rock gets in the teeth or a pinion comes loose and chews up a spur gear.