Quadrajet Problem Solving > Quadrajet Parts and Numbers

Newbie with Decoding question

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tall455:
 Greetings to the forum! I've arrived here by looking for a good Qjet for my 1971 Buick GS. I bought and read Cliff's Qjet book and decided a good base carb to start with would be a 1976 Qjet. I found a nice buy on a rebuilt carb on ebay. The carb number is 17056564 2722. If I am decoding it correctly, it is a 1976 Pontiac auto transmission carb with California emissions. If I am decoding the date code correctly, it was built on the 272 nd day of a year ending in 2 - like 1982. That doesn't make sense to me. I also do not know what is the difference in a "California emissions" Qjet and a "49 state" Qjet. I equate emissions controls with poorer performance. Is there something about this carb that hurts performance that could be modified to make it perform like a "49 state" Qjet? Thanks for any replies.

omaha:
    It seems what you might have is a "service replacement carburetor".  These were made after the original carbs were made and used in dealerships for service replacements. Sometimes theu were made years after the original application carburetor. The ID number of the carb was not changed but the date code stamp changed and indicated the actual build date.  I am not sure of this 100% but  I think some of them were stocked on the shelves at some dealerships to sell over the counter.
     As far as the california carb emmision is concerned, it really does not amount to much. Maybe slightly larger air bleeds and slower opening secondaries. Maybe slightly leaner jets sometimes. BUT, remember, this is 1976 were talking about here. ALL carbs were set up just about as lean as they could run them. There wasnt much difference from the cali carb to the 49 state version. Rochestor was at the top of the heap as far as emission regulations  goes.  I guess they did a few things to make the tree-huggers happy down there in LA-LA LAND and I dont think it really took to much to do it.  The tree huggers were happy with their now slower vehicles and gee, when they went up in the mountains, they were set just about right. (less air = richer mixture) .  anyway, FWIW, dont worry bout the CALI CARB number. All shortcomings can be absolved quite easily.......ENJOY!!

tall455:
 Thanks for the informative reply! My plan is to now disassemble the carb and determine just what jets, rods, etc.. it has. Then I'll post back for suggestions to calibrate for my application. I have a heavy (4000 pounds) 1971 Buick GS convertible with a 455 engine, TH400 automatic transmission, and 2.93 posi rear end. Attached are photos of the carb I.D. # and overall view. I think I have a great starting point to improve upon.

Cliff Ruggles:
EXCELLENT carb, identical to the one I use on my own engine.

Setting it up is easy.  When you are ready, call the shop, provide the carb number, and all the engine/drivetrain/vehicle specs, we will send the correct components so it's basically just "plug and play"!.....Cliff

tall455:
Thanks for the encouragement! Where I have gotten bogged down is in how to get the hole sizes correct for the air bleeds, idle down channel, accelerator pump discharge holes, ect.... I bought a "mini" drill bit set, but it turned out they were too small - just .011 inch to .031 inch. Then I looked at buying a pin gauge set in order to determine individual number drill bit sizes needed, but in order to cover the range of diameter sizes needed, I would need to buy two pin gauge sets: one from .002 to .060, the other from .061 to .250. Together they would cost about $100.00. I need to put that money toward the rebuild kit, not gauges that I would only use once. If I contact your shop with my carb number and information about my car and engine, could they recommend what number drill sizes I should buy in order to get the hole sizes correct for my application? Thanks again! - Robert

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