Actually they exist and the part I listed will work just fine. It's the exact same I ran on my MGT. You just need to purchase two sets of RPM 80010 pivot balls as well.
But don't believe me and simply follow the instructions listed on RPM's site here - I have an Associated Monster GT. How do I...
@cbaker65 the bearings should be firm going in but nothing to crazy. Who makes the aluminum knuckles?
Maybe consider getting a set of the RPM knuckles?