From order of necessicity:
1. P-Dub hard front bumper.
2. Place the steering turnbuckles below the bell crank plate and on the bottom side of the the carrier.
3. Use the Yokomo sway bar open ball cups for the bulkhead side of the camber links. Also, use HPI titanium ball studs on the bulkheads. That way you can just use a hex driver to take off the studs and remove diffs or change roll centers.
4. Use a button head screw for the outer servo mount (where the chassis makes a fin). That will allow the screw to grinde on the asphalt and not the chassis which will eventually snap off. ONLY do this mod if you run on asphalt that is bumpy or low traction.
5. Do a search on this thread for info on how to properly build a diff.
6. If you decide to run a spool, upgrade to either TiR worlds edition CVDs or Rayspeed axles and TC4 bones (which require much grinding, but are very durable)
7. Run 64 pitch gears
8. Get a servo horn with a built in servo saver.
9. Use RPM or Schumacher ball cups for the outer sides of camber links and all steering linkages.
10. Enjoy the best engineered belt driven car on the market. Then laugh at your fellow racers when they struggle to remove diffs or change spurs.
(Disclaimer: This may cause bodily harm if fellow racers are 300lb bikers named Bubba)