[jrunner]

Trying to id this q jet 1970 carb # 7040564 vp 2949. It’s the —- vp 2949 ??—- does anyone know the meaning and can I use this on a 400 engine 4 speed manual trans ?? Engine will be stockish with stock cast iron intake manifold power brake booster hei distributor.

[OG68]

7040564. Automatic Firebird 400 except RA

2949 Julian date code of manufacture. Oct 21, 1969

[jrunner]

Originally Posted by OG68

7040564. Automatic Firebird 400 except RA

2949 Julian date code of manufacture. Oct 21, 1969

Thanks also can this carb be used for a manual trans car?? What’s the difference between a carb for auto and manual??

[Joe's Garage]

Some slight jetting differences possibly, but really just that nipple for the vacuum modulator line hookup.

For a manual trans, just put a vacuum cap on it.

[jrunner]

This is the carburetor what about the big tube sticking up?? Is it for vacuum also. I’m thinking of purchasing this carb. Thanks

[Cliff R]

The large front vent tube started showing up in 1970 on the CA models like you are looking to purchase. They continued to use the large front vent on Pontiac carbs (with a few exceptions like 301's and the Olds 403 carbs) until 1979. The 1970-74 models used a removable front vent held on by a long front screw and shorter side screw. The 1975-79 model large front vent is pressed into a matching hole in the airhorn. It is NOT exactly in the same location so plan accordingly if you are using Ram Air or Shaker set-ups and mixing/matching Pontiac Q-jets between those years.

The vent tube REQUIRES a matching hole in the air cleaner base and MUST be open. Do not cut off the vent or block it off, it needs to be open. With most air cleaner bases you can cut a matching hole for the vent. It will require a seal to keep unfiltered dirt and debris out of your engine.

The 1970 CA models also used a front 3/8" vent to the charcoal canister. That vent can be blocked off or removed and the hole plugged, it is not needed.

The calibrations used on the manual trans carburetors were slightly leaner than the auto's in almost all cases. That really doesn't matter too often as it is extremely rare to encounter an engine from that period that is still completely "stock" where the factory calibration is going to work well anyhow.

I specialize in custom high performance rebuild kits for those carbs with tuning parts. That's about all I'm doing these days and can barely keep up with it. I require ALL of the engine/drivetrain/vehicle specs and the carburetor part number to put one together.......Cliff

[unruhjonny]

As usual Cliff nailed it, but maybe I can add some more;

For 1970 Pontiac's the quadrajet application numbering numbering was fairly standardized and specific - unlike 1969, the carb numbers were more specific to a single engine configuration;

This carb is the "California" version of the 7040264
Note the single digit difference.

The 7040264 & 7040564 were for "bread and butter" 400-4bbl/TH400 engines;

These carbs could found on YS motors on the Firebird (Formula 400) and Tempest/GTO, but these could also be found on the XH engines in the Grand Prix, as well as the Tempest line small valve XV engine, and the full sized small valve XZ engines.
All of these engines were 400-4bbl/TH400.

[jrunner]

Thank you everyone for the quick replies and your knowledge for this carburetor thank you again and have a great day.