[Sower]

I have the XT8 on 6s with the Neu 1515 Heli version right now. It is silly awesome, but you need to know that the end bell is much bigger than the typical Neu 1515. In order to make it fit, you'll need to use Mike's XT8 chassis brace. It raises the center diff up a tiny bit and therefore allows the Heli version motor to be installed. For that reason, I would skip the Heli. Besides, you really don't need the fan when it's set up properly.

Good luck.