Yea I am rebuilding a 3906 RCM monster myself and using two Dewalt 970 motors as well. I have the Kershaw Designs motor mounting plate and I am using the Novak Super Duty XR ESC. I am also using the RCM hybrid bulks with the HPI Lightning hardened diff gear setup. From what I can tell it will all work out just fine for what I want. I have plenty of gearing options due to the stocks that I have built up along the way. Sure it will be a little bit top heavy due to the setup, but it is a basher so who cares. I am planning to mount the battery packs below the chassis in order to compensate for these heavy motors being so high up. Hopefully this will counter act things a bit and lower the center of gravity for the setup. You have the motor already in hand so set it up and have some fun. There are a few guys on here who have already done this project with either Johnson or Dewalt motors and they seemed to have done ok and have had some fun with the project. So enjoy.