Okay this is my recipe for the 19T. I don't have a dyno or anything like that so I can't provide numerical data to back this up. Just lots of track time.
1. Open new package containing a Reedy 19T Spec Motor
2. Solder on some capacitors to the endbell
3. Remove the brushes that came with the motor. Look at the wear on the brushes to see how close they are to being alligned. Allign the brushhoods if you feel like you're able to do it (I don't hehe)
4. Solder Trinity 4499's on. Use the straight serrated 4499's not the diagonal ones. The motor feels better with the straight serrations for some reason.
5. Cut the comm to make sure it's perfectly round.
6. Put the motor back together and shim the armature for magnet center with a little bit of play both ways. We don't want it bindy.
7. Bend the positive spring so that it's almost 180 degrees...more like 170-175 using the eyeball dyno.
8. Run the motor with approx 3V until the brushes are seated. This does not mean until the serrations are gone. Run it just enough so that there aren't super sharp edges on the brush. When their broken it...pull them out of the hoods. Spray some motor spray on a cotton swab (Q-Tip) and clean the face off the brush. You'll see a lot of poo come off with the swab (I don't use a stick because I believe they are too abrassive). RBF gets credit for this tip
9. Cut the comm again.
10. Reassemble, lube, and bolt it into your car.
11. Gear at 5.9 for tracks like Tamiya or 6.1-6.3 for tighter tracks like Socal.
That's it. I hope this helps