72electra Posted February 9, 2004 Share Posted February 9, 2004 I just bought a 72 Riviera and the carb. needs rebuilt I think. I am interested in opinions on wether or not i should rebuild the stock carb. or buy a new Holley or Edelbrock, etc. Can anybody tell me what the CFM on the stock carb is and what kind it is (Rochester, Carter, etc.) I do plan on putting an aluminum intake, headers, bigger cam, etc. on the motor. Will I need a higher CFM carb. with these mods? Thanks for the advice. Marty Link to comment Share on other sites More sharing options...
BigFella Posted February 9, 2004 Share Posted February 9, 2004 It should have a Rochester carb in it. These are great carbs. They take a little more work than a new carb where everything is done for you but you seem to be able to do more with them. Here is a link for identifying your carb and the jetting:http://buickperformance.com/qjet.htmlCheck ebay, you can find ones already rebuilt if you do not want to go that way or old ones that you can rebuild while you ride on the one you have. I have two from ebay, one jetted for 1970 Stage 1 and one from 1971. Plus I have the original from my electra. Link to comment Share on other sites More sharing options...
Turbo Loyd Posted February 12, 2004 Share Posted February 12, 2004 [color:\\"blue\\"] The stock 800 CFM Quadrajet on the 455 in your 72 Rivera should deliver better fuel economy than any aftermarket square bore carburetor. The smaller primaries really help it out. To confirm the proper 800 cfm carb a 3/8 drill bit will slide between the outer booster ring and the throat of the primary bore. On a 750 CFM Quadrajet from a 71 or earlier 455 the bit will not slide through this spot.Please rule out ignition. timing problems etc. before you condem the carburetor. Quadrajets seldom have problems unless messed with by somebody who does not know this carb, or due to little use get varnished up. Other common problems include: bad needle valve, too high of fuel pressure, or mal-adjusted/sticking/sinking float.A good rebuilder at one of our Chicagoland Technical Sessions, was told when he was young that "carburetor" is a French work for "do not touch". I have learned this the hard way, and no longer fiddle with them. There is a guy in Rockford, IL that is very good with these carburetors. Check out his web site at: Quad Shop Hope that helps Link to comment Share on other sites More sharing options...
72electra Posted February 14, 2004 Author Share Posted February 14, 2004 Thanks for the info. I am more interested in performance than gas mileage. I tend to agree that these are great carbs and I will probably just keep the Rochester. I have replaced the plugs and I will check the timing soon. I do know that the choke is not working but that is another issue. Marty Link to comment Share on other sites More sharing options...
Smartin Posted February 14, 2004 Share Posted February 14, 2004 Rebuild the quadrajet...you'll be very happy with it when it is properly tuned.Might want to give John Osborne a call...270-737-4467 JOP455@AOL.COM Link to comment Share on other sites More sharing options...
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