I'm not a fan of the RR 1 piece gear as I've seen more than one break the output shaft off. I'd stick with the gears you have. If you really think you want/need beefier outputs, you can buy 6mm outputs from SuperShafty, you'll need the corresponding driveshafts (or just the driveshaft ends if you're already running MIP shafts) to go with it. I've not felt the need for the 6mm outputs, even running 3500kv on 4s (and every once in awhile 6s!) or a Revolver on 4s. The stock motor plate is aluminum (assuming we're NOT talking about a 1.9" Wraith?) I believe 3mm thick, but it isn't anywhere near as rigid as a 4mm SuperShafty (or other) plate that incorporates the entire backside of the spur gear (same footprint as the spur cover instead of just big enough for the trans bolts to pass through like the stock one.) The stock motor plate's flex was only really noticeable when I was running 48p spur/pinion and the flex would open up the mesh enough to eat the spur, switching to 32p solved that permanently, so I wouldn't call the motor plate a "must have."
I would suggest changing the top shaft and running a slipper eliminator though. The stock clutch tends to slip no matter how tight you make it once you start feeding big power through it, especially if you have the old single disc style. Or, if you would like to run a clutch, switch to a RR 32p slipper clutch/steel spur meant for a Traxxas Slash (it has more surface area and better friction material so it's actually got some useful range of adjustment and can survive a lot of power without slipping.) I prefer plastic spurs and a slipper eliminator myself.
