Worlds Fastest RC Car Challenge take 2.

[JOHNNYMAXXIMA]

Hey guys,
Its that time of year again. going to start to get my truck ready for the event coming up in July. I have already started putting it back together again after crashing it in to the wall last year. New X braces and carbon fiber servo plate went back on last night (courtesy of George from Gorilla. Thanks!).

My question is, looking to get rid of the 2 speed tranny that I have in there now. For top speed purposes, am I better off going to the single speed tranny kit or the Slipperential?
Thanks