need baseplate for thermoquad 750-maybe bushing kit?

I need a baseplate for my 750cfm thermoquad. I noticed that I can basically get the engine to run decently smooth when idling. When I go to give it throttle-it stumbles/ hesitates, etc. I found out after 2 days of messing with it that the throttle base plate-bottom shaft- moves when I use the gas peddle. Hmm-not good. Is there a way to fix this easily? A bushing kit? Maybe just easier to switch out with a good one? I need to get this car running. My main car is giving me problems so I need to get this one going for a back up. It has to have the nozzles for vacuum advance.