Another Rochester Quadrajet Question for our carburator people

[Larry E.]

I have a Rochester Quadrajet #7028207 Code DA which is for a 68 Corvette 300 HP S/T. I noticed
the 69 Corvette 350 HP S/T engine takes #7029207 Code DA. Would this be an identical carburator
except for the year of it being made? If so why it would be for a 300 HP engine one year and a 350
HP for another year? Thanks in Advance--Larry

[Joe L.]

Re: Another Rochester Quadrajet Question for our carburator people

I have a Rochester Quadrajet #7028207 Code DA which is for a 68 Corvette 300 HP S/T. I noticed
the 69 Corvette 350 HP S/T engine takes #7029207 Code DA. Would this be an identical carburator
except for the year of it being made? If so why it would be for a 300 HP engine one year and a 350
HP for another year? Thanks in Advance--Larry

Larry------

I don't have any information that the 7028207 and the 7029207 were absolutely identical in every way. It may just be coincidental that the last 3 digits are the same for both. In any event, all 1968-69 Q-Jets for Corvette small blocks with manual transmission were very similar in virtually all specs and, for all practical purposes, any of these carbs can be used interchangeably.

[Larry E.]

Re: Another Rochester Quadrajet Question for our carburator people

Larry------

I don't have any information that the 7028207 and the 7029207 were absolutely identical in every way. It may just be coincidental that the last 3 digits are the same for both. In any event, all 1968-69 Q-Jets for Corvette small blocks with manual transmission were very similar in virtually all specs and, for all practical purposes, any of these carbs can be used interchangeably.

Joe:
Thanks again for the response. But both of them having the same code of DA tell us anything? Also would we ever find a late #7028207
installed by the factory on a early 69 L46 S/T? What would the judges say on this? Again Thanks;Larry

[Joe L.]

Re: Another Rochester Quadrajet Question for our carburator people

Joe:
Thanks again for the response. But both of them having the same code of DA tell us anything? Also would we ever find a late #7028207
installed by the factory on a early 69 L46 S/T? What would the judges say on this? Again Thanks;Larry

Larry-----


The fact that the broadcast code (i.e. "DA") is the same for both carbs does imply the possibility of some sort of relationship, especially considering that the last 3 digits of the part number are the same. It may be that the specs for the 2 carbs are absolutely identical. If so, the fact that the first carb was used for 1968 with 300 HP and the second for 1969 with 350 HP may only mean that GM decided that a 350 HP 350 cid needed the exact same spec carburetor as a 300 HP 327.

By the way, the GM #7029207 carburetor was used for many years as the SERVICE carburetor for all 1968-69 small blocks

Could an early 1969 L-46 have been equipped with a 7028207 carburetor? I suppose it's possible. What would the judges say? Well, I expect that they'd say it was "not typical of factory production" and expect the owner to document in some way that the carb was original to the car. By the way, I have a friend who is the original owner of his 1969 L-46 built in October, 1968. It has a 7029207 carburetor.

[Edward J.]

Re: Another Rochester Quadrajet Question for our carburator people

Joe, Didn't the Rochester carbs generally end with 202 or 203 as the last 3 digits?

[Joe L.]

Re: Another Rochester Quadrajet Question for our carburator people

Joe, Didn't the Rochester carbs generally end with 202 or 203 as the last 3 digits?

Edward------



Yes, "202" or "203" were common last digit series for Chevrolet carburetors. The first "2" in the ending 3 digit series represents a code denoting a Q-Jet 4 barrel carb for federal emission standards (there were no California standards for 1968-69 carbs). The second digit can be a "0", "1", or "2" and means the carburetor was originally intended for a Chevrolet application. The last digit is more specific as to application and, if an even number, denotes an automatic trans application whereas an odd number denotes a manual trans application.

[William C.]

Re: Another Rochester Quadrajet Question for our carburator people

Not real unusual to see the last number as high as 9 on some low-volume applications, especially as smog rules tightened and the carbs were tunrd more specifically to pass emissions in the early-mid 70's