Cliff's Quadrajet Parts and Rebuild Kits

I had a stone once, don't ever want another, didn't end up in the hospital, but I had a spasm in my back for a few weeks.

    So I've found some more information about these centerplates and weights that is helpful. Mainly that the stamped numbers go up for Chevrolet, Buick, and Cadillac, and numbers down for Oldsmobile and Pontiac.

 In other words, if your distributor rotates clockwise, the numbers face upwards.

 If your distributor rotates counterclockwise, then the numbers face downward.

 That's the way the factory designed it, and after testing each centerplate/weight combination, with numbers up and down, it's obvious that you get much better results with everything set up like the factory designed it.
 
 Almost every one of the combinations performed poorly when I set it up with the numbers down, or opposite of what the factory position is. Most every time the weights did not retract fully into position, leaving them flopping around, so there's no way the advance would return to the minimum setting using just the springs.


  I'll post the results of my tests in the next couple of days. It's not a lot, I only have 7 centerplates and 6 different weight numbers, but it gave me a good idea of which set I need to use to get my timing dialed in to the optimum setting, that being a WOT setting of 36° maximum centrifugal advance, and a cruise timing of 52° all in with vacuum and centrifugal advance.
 Im gonna go with manifold vacuum, and advance unit with 16°, and an initial timing of 10°. The vacuum advance starts pulling at 4", and is all in at 10".

  Something else I noticed is that depending upon which centerplate you use, they can change the position of the rotor in relation to the distributor shaft by a few degrees. I saw this when changing the centerplate and would have to reset my gage to compensate for the change.
 

 I still will need to run the engine to see what the advance curve will be, and I can adjust with springs to get it into the rpm range I need.

 On the vacuum advance units, I figured out how to find out how many degrees it will give you. Most of the GM originals have the degrees of advance stamped into the mounting bracket. Using this, I measured the distance from the edge of the shaft and the edge of the opening where the shaft stops. Each .013" is equal to 1° of advance, so if you've got an aftermarket unit that doesn't have any stamping on it, and you want to know how much advance it will provide, you can measure the gap and divide by .013". So for example, if it'll move  .250", then it will advance the timing by approximately 19°, give or take a degree.

  Hope this helps some.
     Rick

Coil + goes to 12v supply. Coil - goes to the HEI module terminal that doesn't connect to ground. Coil HT to a plug. Plug strap to ground

Chevrolets (the ones that had POE) always had the holes above the flaps.  Pontiac often had them in-line with the flaps.  I've seen them below the flaps on Cadillac carbs. 

On my Chevy carbs, I've run the home-modified notched flaps per Cliff's book.  I've also relocated holes below the flaps on one of my builds.  I've never tested each modification on the same carb to see which method works best.

Has anyone ever done any back-to-back testing on this?  Is it worth the added effort to relocate the discharge holes below the flaps?

I know a bud here selling 1 or 2.

  What exactly is he selling,  and what does he want for it?


 Still in the hospital, but hope to get sprung tomorrow if im lucky. Kidney stones can really do a number on you,  if you've ever had one you'd know what I mean. 
 Thanks for your help.

 Rick

You can put in the jet size wanted where it asks for the carburetor part number....