1968 quadrajet what should i do now??

[Brett W.]

I need a little advice on the best way to fix this problem. I just put a quadrajet on my 68, 327, 300hp. I pulled it apart and the carb was in great shape for a 68. except the throttle plates. Long story short, I found out that the primary throttle plate shaft had been reworked with new bushings. They must have drilled it wrong and offset the throttle plates. Then filed out the bore a bit to try and make them close. I was able to make it better but the throttle plate asy is junk in my eyes. Looking in at the primary throttle plates they do not have a nice even space around when closed. Close put not perfect, I would assume this would make it hard to get a good idle. Should the space around the primarys look just like the space on the larger ones?
Can you get a new throttle body, complete for this carb. I have looked at swap meets for used ones but not happy with what I see. Any advice would be great.
Carb number is 7028212

[Joe L.]

Re: 1968 quadrajet what should i do now??

I need a little advice on the best way to fix this problem. I just put a quadrajet on my 68, 327, 300hp. I pulled it apart and the carb was in great shape for a 68. except the throttle plates. Long story short, I found out that the primary throttle plate shaft had been reworked with new bushings. They must have drilled it wrong and offset the throttle plates. Then filed out the bore a bit to try and make them close. I was able to make it better but the throttle plate asy is junk in my eyes. Looking in at the primary throttle plates they do not have a nice even space around when closed. Close put not perfect, I would assume this would make it hard to get a good idle. Should the space around the primarys look just like the space on the larger ones?
Can you get a new throttle body, complete for this carb. I have looked at swap meets for used ones but not happy with what I see. Any advice would be great.
Carb number is 7028212

Brett-----

It might just be a case of the butterfly valves being mis-adjusted. It's not always so easy to get these right. As far as the "space around the primaries looking just like the space on the larger ones", I would say it should appear ABOUT the same.

As far as a new throttle body assembly, none have been available from GM or Delco in years. There are no aftermarket pieces I know of, either. This means that to get one, you need to find a good used piece. There are plenty of these out there as the one used on your carb was not unique to Corvettes. However, there are LOTS of different ones used over the years and huge number of models of Q-Jets manufactured, so you have to match up a used one with the one you currently have.

What about NOS? Well, if you can find a GM #7036406 if your car is manual transmission or GM #7036407 if it's a THM-400, then you'll have what you need. Don't hold your breath until you find one of these, though.