CAClark, the upgrades I have are the HPI Carbon Fiber Chassis, upper deck, F/R shock towers, HPI front one way diff, Castle Creations USB, HPI aluminum wheel hex's, HPI threaded aluminum shocks, HPI D-Box, and what ever parts that come out to make it better and faster... I will get. Havent ran it yet buy I will tru out the Castle Creations and see how it works out.