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Discussion Starter · #1 ·
I have a 1963 Impala, Automatic ,283, 2 barrel and dual exhaust. The carb on the car now is a rochester 2 barrel #7013878.
My chevrolet shop manual says I should have a 7023008 or a 7023018 with #56 jets.
Can someone identify this carb 7013878 ?

My car is getting about 12 MPG now. I would think I could get maybe 18 mpg with the correct 2 barrel carb.
 

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Do a Google search on your carb(s) .. There is one on E-Bay right now,,
Nice car.. I would keep it a close to stock as I could even if it means retaining the 2BBL... Have you thrown a tune up at it and at the same time a vaccum guage to get your highest HG might get yah some MPG..
T.
 

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impalaman63 said:
I have a 1963 Impala, Automatic ,283, 2 barrel and dual exhaust. The carb on the car now is a rochester 2 barrel #7013878.
My chevrolet shop manual says I should have a 7023008 or a 7023018 with #56 jets.
Can someone identify this carb 7013878 ?
Are you getting the carb number from the metal, triangular tag under a screw head, or is this the number from the casting itself?
 

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You can only trust rochester numbering about 80% of the time. I've had some that were stamped for a manual transmission on an automatic car, and I know they were originals. What happens (or at least what seems to describe it) is that they needed more carbs for the chevy automatic line production. They are running low, but the Pontiac plant has 1200 set up for manual transmissions. They send them over to the chevy plant where they do a quick metering spring and jet swap and plop them on a 283.

I think 18 mpg is not out of the question, but you're not getting 12 mpg because you have the wrong carb, you're getting 12 mpg because your carb isn't tuned properly. The number stamped on the carb means almost nothing. They are mostly all the same carb, just stuffed with different guts. Put the right guts in your carb and you'll be good. No carb is a bolt-on thing. They all require tuning, even when they installed them at the factory, so getting another carb won't be the answer. Might as well tune the one you have.
 

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My point is, the OP may well have the correct carb- but if he's going by the casting number as opposed to the correct "tag" number, it will not look like he has the right carb- even if he does.

But either way, tune it (especially jets- which seem lean enough- BTW, and float level), for the 283 and see what that gets you.

A lot can be had, mpg-wise, by tailoring an advance curve to bring in timing earlier and as quick as the gasoline, quench and CR will allow.

If the vacuum advance isn't already, run it from manifold vacuum and set the total advance (w/o vacuum advance of about 10-12 degrees or so) to about 36 degrees.
 

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Discussion Starter · #8 ·
cobalt327
Tag # g937 casting number 7013878 this is whats on the car now.

curtis73
Can I buy the kit for the 7023008 carb and install it in the 7013878 carb I have on the car now?
The shop manual says #56 jets for the 7023008 carb I will have to open up the 7013878 carb and see what jets it has.


On the car now.
 

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impalaman63 said:
cobalt327
Tag # g937 casting number 7013878 this is whats on the car now.
Just for the record- neither of those numbers are the actual carb number.

One is a casting number, might be shared with literally dozens of other carb "tag" numbers. The tag is a reman tag and is numbered differently than how Rochester tagged their carbs, obviously.
 

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impalaman63 said:
curtis73
Can I buy the kit for the 7023008 carb and install it in the 7013878 carb I have on the car now?
The shop manual says #56 jets for the 7023008 carb I will have to open up the 7013878 carb and see what jets it has.
No... well, maybe but you can't be sure. But simply rebuilding a carb with the kit from an 008 won't change anything. The kit doesn't come with jets, especially because that carb might come in a wide variety of cars with different jetting.

Find someone with a two-gas analyzer (sniffer) and tune it using CO2 profiles.
 
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