Rochester 2g Mismatch

When removing the carb. from engine, checked the number on it. The carb is a 7036146, according to a post on here, this carb is for a Buick 300-350. I have sourced another carb which is s 7027082 which is listed for a 225.







Comparing the two carbs, they are the same. The 225 carb is on the right. The castings look the same, linkage, everything.







I got a tracing of a 2G that goes on a 350 from a member on here. The carb 7036146 listed for a V8 does not fit the tracing and the 225 intake is different than the 350










The carb that is listed for the 350 is in better shape, would like to use it, but there was a thread that stated that a carb over sized for a engine was not good. Trying to sort out what is going on with the carbs. Any input.

 

If it were me (and I was desperate) I would put the throttle base from the 225 onto the 350 carb. I am not sure if the venturi difference would cause a severe enough turbulence to notice. I would also swap the jets from the 225 to the 350 and give it a try. Don't seem like you really have anything to loose. Now I have not tried this but would be interesting to find out.

 

There's a lot more to a carb than just venturi and jet sizes. Idle ports, air bleeds, accelerator pump nozzle....there's a lot of things that come into play.
Having said that, I'd question whether that carb is from a Buick 350. I can't imagine a Buick of that era with a manual choke...

 

Talked to a couple places that rebuild carbs. They said to rebuild carb that is listed for engine. I just can not comperhend how idenitcal these carbs are, yet they are different. Looks like I have a V8 carb for something

 

No doubt it's best to use the carb designed for the engine. I know there has to be thousands of old cars that ran for years with holly carbs which was maybe a few cc from exact. Doug the internal difference as I see it is not critical on what the OP is wanting to do. I still say I would try it before I shelled out 2-3 hundred for a replacement carb. As far as the top having manual choke well that top may be off a 225 carb. They are interchangeable.

 

Does any one have any information on CFM on the two carbs.

Going to stop by the guy that is rebuilding my engine. Have him look at the internals and see if they show anything that does not look right as for as wear.

 

No mounting boss on the baseplate for an auto choke...I don't think a Buick ever used the divorced choke on the manifold.
I think the listing is wrong and it's a 225 carb.

 

Are these carbs module, where top,bottom and middle can be interchanged to any 2G carb, V6 or V8?

 

I plan on rebuilding the carb myself, so cost will be minimum

 

There are 2 different sizes of the Rochester 2G series carbs-the smaller one was used on the 225, and various small GM V8's
It has a 2 5/8 air horn diameter (where the air cleaner sits)
The larger one was used on most 2bbl V8 applications and has a 3 1/16' air horn diameter.
The mounting bolt pattern is slightly larger as mentioned above. Some small parts such as jets will interchange but the main body and throttle plate are different.
Here's a side by side comparison (note these are Pontiac carbs, not Jeep)



Edit-I used my Google-fu and found a listing for 7036146, on a 66 Buick 300 with auto trans.
It's shown as a 2GC (auto choke) but as mentioned above, the top could've been swapped.
And I found a picture of a 300 Buick with the goofy throttle arm like a Jeep has.