Do I have a 73 SD q-jet?

[stevef]

I forgot about this q-jet that was sitting on a shelf in my parts room for years. Finally I noticed it sitting there today and with Cliff's book, I translated the number, 7043262. So, it's a 73 Pontiac, Federal, automatic trans application. Julian date, 2312, translating to Aug. 19, 1972.

It looks just like the photo showing the bracket for the choke pull-off on page 11 of Cliff's book, that was described as a 73 SD carb. So, have I lucked out and have a 73 SD carb? Any other clues needed to make sure?

Looking at the carb from the front, to the right of the fuel inlet, there are 2 small empty holes in the front of the body, that I thought were maybe holes where the vac tubes had pulled out and were missing. But, I see in Cliff's page 11 photo that it has the same 2 small holes being empty as well. What are those holes used for and should they be plugged or are they used for vacuum sources, and if so how can they be without tubes stuck in them? Thanks!

[Cliff Ruggles]

Unfortunately, it's just the standard Pontiac V-8 auto trans carburetor for that year.  The Super Duty part numbers were 7043270, and 7042373.  They also made Service Replacement SD carburetors, part numbers 17054910, and 17054911 (going by memory here, but I'm pretty sure those are the numbers.)

The 1973 and 1974 Pontiac Super Duty carburetors were the first "800" cfm castings that used the outer booster rings.  They made a brief run of "800" cfm carburetors in 1971 for the HO engines that were special castings that didn't use the outer booster rings.

Far as I know, the 73 and 74 Super Duty carburetors were also the only early design hot air choke large cfm castings.  They are pretty rare carburetors, and pretty valuable as well......Cliff

[stevef]

Oh well, that's okay. It's good to know what it is. Thanks Cliff.

Any idea about what the 2 empty small holes on the front right side of the main body that look like vacuum source holes are for and how they are used?

[Cliff Ruggles]

I'd have to go to the shop and look at one.  Some do have a ported vacuum source there, but they also had bosses to bolt down a fast idle solenoid bracket, at least from what I can remember about them?.....Cliff

[stevef]

I think you're right about the holes being for mounting a fast idle bracket. The holes are threaded. Here's a pic. Thanks alot for your help:

[65WildCat]

Sorry to high jack, How many of the SD carbs were made?

PONTIAC SD-455 ENGINE PRODUCTION FIGURES
MODEL                         4-SPEED              AUTOMATIC         TOTAL
1973 Firebird Trans Am          72                    180                 252
1973 Firebird Formula          10                     33                    43
1974 Firebird Trans Am         212                    731                   943
1974 Firebird Formula          n/a                     n/a                    58
         
                              TOTAL      n/a                     n/a                  1,296

So, Would this mean the same amount of the SD carbs produced + a few replacement #'s as they weren't used anywhere else...

[omaha]

where did the K/D switch for a turbo 400 get mounted to? just a thought, I used to have one and I can't remember.  You are correct that those are for mounting something-most likely the solenoid. I have some (carbs) similar but not exactly as yours in the pic.

[Cliff Ruggles]

Yep, those holes are for the fast idle solenoid bracket.

Not sure about production numbers for the SD carburetors.  I've seen quite a few SR units, made in and after the model year run.  Doesn't seem to be any shortage of them.

Not sure about the  K/D switches.  Some early q-jets used a bracket from the carb linkage, most of hte later stuff must have been attached to the accl pedal inside the car.......Cliff

[65WildCat]

Sorry to dig up an old thread, my question relates to the '73 - '74 SD carbs...

Do they have an adjustable APT system that can be utilized?

Is it set at the factory, similar to the large '71 - '74 Buicks..

Where is it located?, if so?

[Cliff Ruggles]

No APT system was used on the Pontiac carburetors prior to 1975.

They did use an adjustable upper idle airbleeds screw in the airhorn, but it does not work the same was as an APT screw........Cliff