[impalaman63]

I have a 1963 Impala Convert with a 283 Rochester 2 Barrel Carb. How many CFM's is the stock rochester carb? If you do the math you come up with 409 CFM-----> (283 cu in X 5000 RPM max=1,415,00 / 3456 = 409 CFM)
I can find a 4 barrel Holley # 0-8007 with 390 CFM and a 2 barrel Holley 0-7448 with 350 CFM also might be able to use a Holley 2 barrel 0-4412c with 500 CFM My other question is what happens if I use the 500 cfm carb on my stock 283 ? Will it be over carb- ed and maybe bog or use to much gas.
I 'am not looking for more power just a better crusing carb for this car.
Thanks Dan

[barnym17]

About 250 to 300 cfm at the 2bbl. rating, you would be better off to find a q-jet manifold and q-jet to put on it. It will not over carb due to the air valve design and will probably pickup both mileage and power.

[impalaman63]

Would a 450 CFM Spreadbore Economaster Carb be a good choice?

[johnnya]

Is the original carb not performing properly?
JA

[poncho62]

A 500 cfm 4bbl will not be overcarbed for a 283....You will have to change the intake for a 4bbl......an Edelbrock Performer would be a good choice. Will take spreadbore or squarebore.

[impalaman63]

I'am getting about 11 MPG with the stock 2 barrel carb. Thats why I was thinking of changing to a better setup.

[barnym17]

My personal opinion is that the q-jet will better for mileage and performance.

[hardhatz]

Q-Jet
They even put them on 2.8 Mercedes-Benzes in the 70s, and they were not overcarburated.

[impalaman63]

What was the 1st year of the Quadrajet intake manifold?
What would be the best year Quadrajet Carb to buy for a 283 ?

[poncho62]

65 I believe.............That one in the picture is a later one....maybe 68-74, judging by the lack of oil fill hole and spring choke setup. It would work on your 283, but you would have to get valve covers with an oil fill access.

[impalaman63]

What would be a better choice the 1965 quadrajet ntake
or the 2101 edelbrock performer
Also what year quadrajet carb should I get . Going on a stock 283 dual exhaust

[baddbob]

Originally Posted by impalaman63

Would a 450 CFM Spreadbore Economaster Carb be a good choice?

These are really good carbs for a mild street smallblock, it'll work excellent on that 283. I don't think Holley has made them for quite awhile but it was very common to find them under hoods in this area years ago. Usually ebay has a good selection.

[poncho62]

I would go with the edelbrock....if nothing more than, you can bolt either a spreadbore (Quadrajet) or squarebore (Holley, Carter, Edelbrock) to it........

The Quadrajet that you are looking for is a pre 75 (I think)....the serial # will start with 70...not 170.......The sreial # is stamped up the side of the back barrels on the drivers side of the carb.

Love the car BTW...I have a 62 Canadian Pontiac which is very similar.

[impalaman63]

poncho62
Nice car. Have you ever been to the Back to The 50's in MN one of the BEST car shows around , 11,000 plus cars each year. Next years show June 20,21,22 2008 Check out the web site at http://www.msra.com/

[hardhatz]

What would be a better choice the 1965 quadrajet intake?

You could also get an aluminum stocker from an 80s 305 Q-jet Camaro for almost nothing. The carb & air cleaner from the same car would work well.