duratrax bearings
The Duratrax bearings are good. I have had trouble with the rubber sealed bearings that come with the TC3 Racer and replaced with the Duratrax without any problems.
There isnt alot of weight reduction to do if you already have the composite outdrives. The biggest (and most overlooked) way to save weight is with your body, use as little paint as possible. It also helps to use lightweight electronics like a GM V12. Keep your wires short because copper wire is heavy.