Rebuilding the Rochester 4GC on my 60 Super 88. I see that the primary float is supposed to be somehow connected to the power piston via a tang and spring. These parts are no longer there. I can see where the tang was removed from the float by someone else. From what I've read though, the power piston is actuated by engine vacuum. So, I'm trying to figure out what the purpose of the float/power piston connection is. And if I should put it back together without it or try to locate these parts and do it right. Thanks for any help!

 

From the Rochester 4GC service manual:

 

Thanks, Joe!

 

Tony,
It seems there are a bunch of different variations. I just finished doing a 4GC for a 65 425. The incorrect carb that was on the car did not have the "tang" The correct number replacement did. Seems like some carbs have it and some do not. The manual that Joe link to was very helpful. I have probably done a hundred Q-jets but this was the first 4GC I had ever seen.