Hello, I recently purchased a 72 Stage 1 that does not have the original/correct carb in place. Car is a factory 4 speed. It has what decodes to be a 1974 buick 455 carb ( running VERY rich) . I have purchased a 1972 Qjet which also decodes to a Buick 455 . Niether is a stage 1 carb. I cannot locate either a rebuilt or rebuildable one for my car. Is it reasonable to think that I can use one size larger jet and updated metering rods to "duplicate" the stage 1 carb? My 72 carb is one digit off ( 0 instead of 2 at the end). Also, the small tab that sticks up behind the secondaries on the air horn was broken off on the 72 carb. I can't find any info on what this does and if that is a problem. Can the 74 cover replace the broken 72 one? The 72 carb is supposedly rebuilt, but I haven't tried it yet. Sorry for lots of missing info. I am not strong on carbs and nervous about investing in the wrong one(s). Thanks, Steve
The 72 Stage 1 carb came with 75 primary jets, your carb probably has 73 jets. Please post a picture of broken tab. I would not swap air horns, even if they look the same as there can be differences in air bleeds and such.
My 72 Chassis Service Manual says the following are also differences from 455 to 455 Stage 1: 0.045" primary metering rod (Stage 1) vs. 0.044" rod (Non Stage 1) CV secondary metering rod (Stage 1) vs. CT rod (Non Stage 1)
Thanks for the info. I assume that my carb can be "converted" based on these responses. I will post picture of the tab that is broken. This will be a street car with no intention of race duties. Cruisse night kind of car mostly. Given that, would I need to play with metering rodsto achieve drivability or can I just use the #75 jets? In any case, a rebuild is likely. Thanks, Steve
If you don't change the primary metering rod also, you will be running unecessarily rich. The primary rod fits inside the jet, so the overall fuel flow area is the jet size minus the rod size. A 0.001" undersized primary rod size isn't the end of the world, but small differences such as this might be felt... if not by your right foot, then by your fuel mileage.
...on the other hand, a little rich might help depending on your car. I neglected to notice that you said the car is a 4 speed. I believe that the 4 speed carb is set up a little different... I'll check service manual again.
Thanks to all. I ahve attached photos that show ( I hope ) the damage I noted in the original post. My sense is that this won't have any effect, but I can't honestly tell you what the protrusion did in the first place. Thanks for any add'l help. Steve
There is no difference between the 455 carbs in 72. They are all the same. Only jets and metering rods are different and they carry diff. part numbers for that reason. It should be easy enough to find another good 72 carb that has the air horn without broken tab.
There is one difference in 72 455 carbs, other than the jetting and metering rods. The CA emissions carbs had an extra nipple for the EGR valve.
i want to know what type of carb i should go with for an everyday driver somthing that i can stomp on and have the power but still do good for just crusing around, i have a 455 bored over to a 464 any suggestions?
Please check out my post in the Bench section; it's titled Hi Buick guys..... I may have what you want. The one I have is setup pretty lean now, easy to change though. If I wasn't semi-retarded about computers I'd have a link but
