The new latest spec clutch kit from UFC for your HPI BAJA, this bell accepts TR style pinions
 
This kit has been winning races across the world in 4x4 race trucks, so in a light 2wd baja the difference will be insane. Get the jump on your friends and youll be able to run an extra pinion tooth without loosing acceleration over standard 54mm clutches.
 
The Bell is designed with a recess on the inside so that you fit a socket cap retaining bolt through the inside of the bell and lock the pinion in place with a nyloc nut to prevent it coming loose.