69 BB Q-Jet question

[Greg L.]

I'm sort of looking for a correct carb for my car that was built Jan 31/69 with the engine built around the middle of Jan. Obviously the carb has to predate the car by at least a week or so but can it be dated after the engine build date? Also is the fourth digit in the P/N for the year of the carb manufacture, or for the model year that it was intended for? For example, since my car was built so early in the calendar year, could it have had a 7028204 carb with a high date code? I'm just trying to determine what the correct numbers would be for this car of mine so that when I do come across the correct one I will be sure of it. Any help is appreciated.

[Mike M.]

Re: 69 BB Q-Jet question

Greg,
First, I am not sure if the carb can be dated after the engine build date, but for the carb itself, the fourth digit is the automotive model year the carb was intended for use on. Rochester built replacement carburetors for service that used the same model number. Example,I have a 7029207 carb in my stash that has a manufacturing date of January 1977, so it is obviously a service carb. The year of manufacture of the carb is the last digit of the four digit date code.
Mike

[Jack H.]

Yes, CAN be dated after...

Engines were run-in/tested at Flint & Tonawanda using a propane 'hood' (cleaner/easier than mounting a carb and 'plumbing' gasoline to the hot engine test stand). You'll see the carb, as an assy, going onto the engine in your copy of the AIM (Assy Instruction Manual) which says the carb didn't meet its engine until the two got together on the power train feeder line at final assy in St. Louis. Same goes for the fuel pump and other engine accessory 'bolt-on' items (starter, alternator, Etc.). So, these components (finished engine + bolt-ons) were pulled for inventory pseudo randomly in St. Louis.

[Greg L.]

Re: Yes, CAN be dated after...

Thanks guys, that cleared up a couple questions. So I guess that a 7029XXX IS the proper carb for a 69, however the date on it for my Jan31/69 car could be from 0009 to around 0209 for a carb actually built in 69 and then say around 1708 to 3658 for the same part numbered carb but actually built in 68...correct?

[Harmon C.]

Re: Yes, CAN be dated after...

You are correct. I would like a Dec. or early Jan. if I was looking but 6 months is the rule. Lyle