i've run the 1515 1 Y smooth can in my rustler with 6S...if you run the extended rear a- arms w/or in addition to integy 17mm adapters, there isn't even a wire clearance issue.
i however, don't really recommend a 1515 for the rustler....it's like putting a jet engine in a honda s2000.
Ouch!!!!!!!! you're crazy man The stock slidder drive shaft should take a beat