There are two varients of primary metering rods for the Q-jet. Rods used with 70xxxxx carbs are longer than rods used with 170xxxxx carbs, hence, they are not interchangeable. Replacement rod part numbers correspond with carb numbers, rods whose part numbers start with 7 fit 70xxxxx carbs. Rods with part numbers starting with 17 fit 170xxxxx carbs. If your starting with a randomn assortment of rods, the longer rods fit 70xxxxx carbs.
The last two digits of any rods part number corresponds to the diameter of the rod at its "leanest" point. Each rod is stamped with these same two digits.
Following the rod diameter stamping is a letter denoting single or double taper, and the tip diameter at its richest point.
"A" Rods are single taper, "B" (and all others) are double taper.
All rods, except those noted below, have a .026" diameter tip.
"M" =.032" diameter tip
"50D" has a .036" diameter tip

Information Taken from AC Delco catalog 9A-100, "New Carburetors, Carb Kit and Parts". Verify any information. Transcription errors may exist.
AFAIK, the above rods are still available at your AC Delco parts counter.

-If you are looking to build a Q-jet to exact stock specs for your vehicle, the AC Delco dealer has the ability to look up exact applications and provide stock configuration information. (Primary rods, jets, secondary rods, hanger, etc.)
-If your vehicle is close to stock, 99% of the time the primary side of the Q-jet can be left alone to retain decent light throttle characteristics.

This information is only intended as an overview and may not include all the necessary information, data, or facts.
Every vehicle is unique, and research for your particular vehicle is recomended.

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This Page Created By Alexander M. Bilan (gmguy89@netscape.net)
June 12, 1997
Revision 1.0 June 12,1997