Hi , i'm living in France and i own a 1966 Buick Riviera GS , the carburetor is a Carter AFB but i dont manage to identify what model it is , because i want to know his specifications and performances , and i want to know if this carburetor is the original . I give you the digits an letters i found on the carburetor : - 3923S - 01721 - M4 thank you for you help
http://buickperformance.com/carter.htm http://www.carburetor.ca/carbs/catalog/Buick/Buick8-1961-76.htm Here are a couple references for you. The 3923 series carb, is grouped in with the AFB's from 1967-61. The other codes you have could be the build date, and that would tell you if it is numbers matching!!
Wrong carb on the Riviera--3923S is from a 65 425AT. The 66 used a Rochester Quadrajet. Intake manifold must have been changed also. John
Hi, thank you for your answers ! Maybe the carburetor was changed and the intake manifold too , but it could be the original for my car , because this car is an export model , sold new in France . So the question is : were export models sold with differents carburetors ? An other indication : the motor is painted in red and the intake manifold too , so : - is this color an original one for a '66 Riviera ? - is it possible to change the carburetor without changing the intake mpanifold , even it wont work as well as it will with the Q-Jet ? Thank you .
I can't find much info on engines in export models. The 66 chassis manual has reference to a "MV" code low compression 401 for export but doesn't give the details on it other than 8.75 CR. There is no reference to an export version of the 425. Have you checked what engine is in your car? The code is stamped on the block in front of the valley cover. A 1966 425 would be coded "MW". If you want to change to a Quadrajet you will have to replace the intake manifold. John
Hi John , thank you ,can you tell me what means " 8.75 CR " , and " valley cover " . I looked at the block , but i didn't found any code . I will have a look on the identification plate fixed under the hood , maybe it will give more informations .
Hi, 8.75 CR is the compression ratio for the export version of the 401 made to run on "regular" lower octane gas Check here http://www.teambuick.com/reference/library/66_chassis/00-a.pdf on page 00-4 for a picture of where to look for the engine code. The 2 letters in the "production code" indicate what engine is in your car. John
Hi John , i looked at my motor and here is what i have found : 1 the engine code production is : MR 418 2 the VIN seems incomplete i have only found stamped on the block : 6H594417 3 My car is an export model , so there's a plate attached under the hood on the passenger side where are writen these indications : General Motors France , Make : Buick , Model ; Riviera , Serial number : 494876H911277 4 Head cast number is 1374603 I think that the block is not the original one because numbers are differents on the block and on the plate ,( but the number on the plate is correct for a '66 Riviera ); the production code is for a 400 CI but the casting number on the heads is for a 401 or 425 : and so the carburetor number indicate a '65 425 !!!
The "MR" code 400 is a 401 that was down-rated to comply with GM's corporate rule on maximum size engine to be used in an A-body car, i.e., the Skylark GS. Almost all its parts are same as the 401. As you noted, it appears the engine was changed on your car. If it were mine I would leave it as is if it runs well. John
Hi John ,thank you for these indications; yes the engine runs well , i had a trip the last week , 450 kilometers on highway , running at 130/140 kilometers / hour , without any problem . So i will keep this engine for the moment . If i can buy it in the future , i'd like to get a 425 CI with a 2x4BBL !!!
