The carb i have is 7040240 i know it is a 70 buick carb but what i,am tring to find out is what is the MD 0350 that is also on the carb by the part number.
MD I think is the intended users code. The other numbers are the date code by the numbers of days into the year it was made.
I believe that is Feb 4 meaning the 35th day into 70. I have also read that the codes like MD were that plant code for where Rodchester made them so I am not guanteeing that any of this is correct.
Jim i found out the MD is the plant production code. You are wright on the date code 035/0 035 is the 35 fifth day of the year and the 0 is the year. Thanks for your help.
I saw this which seems to go the other way: carbking 11-09-2005 08:42 PM -------------------------------------------------------------------------------- md1twal3 - since I have been quoted (no, I don't object) on this thread, I guess its time to jump in and try to clear up a couple more details. First - the meaning of the term "plant code" on the carburetor. As stated in the quoted email, the plant code is a code used by ALL assembly plants in lieu of the 7 digit carburetor number. It is NOT a code representing a specific plant. The engine came down the assembly line with a "build sheet" or a "broadcast sheet". There are boxes on this sheet with a two character code for the various components. This code is similiar to the 2 character code stamped on the front of the block. Second - question is there a place on the net listing what all the plant codes mean? I SINCERELY HOPE NOT!!! Believe it or not, restampers also own computers and surf the net. This type of published information will COST the novice restorer who buys a "correct, dated, and plant coded" RESTAMPED ram air carburetor for a "substantial savings over the gouging dealers" and doesn't know the difference; puts it on his car; takes the car to a national show; and gets tossed out of the show for attempted fraud by a judge that does know the differences! This information for a given car is on the build sheet, one of the most important documents you can locate with your car. The restampers do not have all of the build sheets. Third - question concerning the date code and the two month "window". Answer is personal opinion, based on restoring these carbs for the last 30 something years. OPINION - The two month window is a very good ballpark for high production automobiles (eg. Catalina 400 A/T). The two month window does NOT hold true for low production vehicles. Best example I can cite would be 1969 RA IV manual transmission carburetors. Remember that the 1969 RA IV engines had approximately an 18 month production run (the Firebird continued the 1969 model year through 31 December 1969). I will grant that I have not seen every 7029273 carburetor made, but I have seen a lot of them; I have only seen 5 different date codes. Given this information, the two month window does not make sense for low production cars. Jon.
Here is another: Of course, you can say that now you have received another "opinion". Let me offer some proof, and I have researched this issue in depth. There is a "plant code" stamped on each original equipment carburetor (it is not stamped on the later production service replacement carburetors). This plant code is the code that the assembly plant used in lieu of the actual carburetor number; not a code for the plant producing the carburetor. The plant code is a two character code. This code WILL be found on the "build sheet" for your car in the box titled "carburetor". I have viewed build sheets as late as mid-december 1969 (remember that the Firebird had 1969 production through the end of the calendar year in 1969, 1 January began the 1970 models). ALL of these build sheets agree with the information above. If you have your build sheet, you can easily verify the correct unit for your car. Finally, while I have no affiliation with the national Firebird clubs, I am tech advisor on carburetion for GTOAA, and the above is what is used in judging these cars by GTOAA. This is one of the anomalies of the Rochester numbering system, where the 4th digit is not the year of the carburetor. The first production of the 7028270/73 was for the RA II 1968 cars, so it is possible to find these carburetors with 1968 dates, as well as 1969 dates. Regards. Jon Hardgrove.
Jim - looks like you found some of my posts from the Pontiac boards. The ones you found pretty well cover the "plant code". Date codes on Q-Jets will be of two types: (1) the codes used on Rochester-built Q-Jets which are "jjjy" format (2) the codes used on Carter-built Q-Jets which are "my" format For the Rochester-built Q-Jets, the "jjj" represents the Julian day of the year. 001 would be 1 January and 365 would be 31 December (for non-leap years). 035 would be 4 February. The "y" represents the last digit in the year (in this case 1970). For the Carter-built Q-Jets, the "m" is a letter that would represent the month. A representing January, B February, etc. As with the Rochester-built Q-Jets, the "y' would represent the last digit of the year. Jon.
Jon and Jim thank you for all the info. I bought 2 455 this last week for my personal stock and one came with this carb. so that is why i was asking about the codeing on the side. What would be the value on this carb all parts are on it and the air horn looks real good where the front bolts go thru.
