Most definitely at least buy steel transmission gears!
As far as drivetrain goes the Spawn has the better slipper with 32p pinion/spur gears and heavy duty driveshafts, but the trans internals are the same as the others. I have the Roc412 and MMP on 3s and I didn't make it through one pack before I shredded the puny idler gear. I was not being too incredibly hard on it. I was on grass doing wheelies. Now its down waiting for the HR light weight steel gears to arrive. I have Robinson Racing internals on my main SCX-10 and they are holding up fine. I just wanted to try something different on the Wraith.
As far as diff gears are concerned, I don't know how the standard gears hold up to this kind of power. I have not had any problems with them on my SCX but I am not running big power through it. I did swipe the HD gears from my Yeti and they are going in the Wraith, along with my SSD rear axle. That's just a precaution because I know they are strong. Eventually I will get spools for it too, but I've already blown my RC funds for the next few weeks.
Aren't the Spawn kit transmission gears already steel? I haven't unpacked everything so I don't know for sure, but I thought they were. So you haven't had any problems with your stock drive shafts?
Also, is it worth upgrading the bearings, or are the stock ones just fine?
Maybe I should just build this as is and see for myself what breaks!
