Originally posted by Don Shillady
Tech1,

Out of your vast experience would you please make some further comments regarding the Quadrajet? I have a dirty one from a '76 Corvette (assuming that is a Q-jet) and planned to refurbish it for use until I can buy a better new one as either a Holley Avenger or Edelbrock carb. I am expecting to basically just dunk it in carb cleaner and maybe replace a gasket or two. I am joyfully venturing in over my head building my '29 from large pieces, but now realizing that I don't know a lot of the fine details such as where to attach the vacuum for power brakes and how to hookup the kickdown cable to my TH350. After considering your advice for a Streetmaster intake and communication from Edelbrock, I am probably going to play it safe with a Performer intake, but it is my understanding that the Q-jet will bolt on the Performer without problem. While I reserve the right to make my own decisions based mostly on economic considerations, your advice and that of others on this site have already proved to be extremely valuable, so I look forward to a "few good words" regarding the Quadrajet.

Don Shillady
Retired Scientist/teen rodder
I rebuilt many Q-jets.... It's a very capable carb, and it isn't that hard to trick out.

You can buy a full rebuild kit, which comes with all gaskets, new check-ball, accelerator pump, float, measuring tool and guide. It costs $40 bucks here in Canada, so its probably like $2 USD . Just write down the number on the side of the carb body so they can give you the proper kit.

You'll get an exploded view of the carb with the rebuild kit incase you forget what goes where.... When you dis-assemble the carb, do NOT bend the rods for the accelerator pump to remove it - there is a pin that you can drive out with a small punch, and for most others theres a small clip.

Get the carb hot-tanked after you dis-assemble it, regular carb cleaner stuff (or varsol even), requires a lot of scrubbing to get the carb really clean. Hot tanking comes out looking new

The power brakes will attach to the FAT vacuum outlet on the base-plate. It may be threaded on some carbs.

For the kickdown, you should have the bracket with your carb on the side where the throttle cable clips, if not, head to a wreckers yard and take the brackets off a 70's car with a TH350.

I plug all other outlets that arent being used.


As for modification;
On the primary side, all you do really is change jets/rods for the approriate mixture, modify the accelerator pump, and the power circuit spring to suit your vacuum at idle.

All other modification takes place on the secondaries.
The secondaries require two "specialty" drill bits (1/32 and 1/5), grinding bits, brass plugs, homemade "tool" out of aluminum rod, etc etc....

Buy a book called "Rochester Carburetors" by Doug Roe, published by HP Books.... It explains everything very clearly. Its what I started with and its still what I refer to whenever I deal with Q-jets.
http://www.amazon.com/exec/obidos/tg...books&n=507846
Good Luck