Rochester 7023031 carb

[John Morris]

I just bought a 63 Fleetwood. The carb is a beautiful rebuilt Rochester number 7023031. I thought the 63 had a Carter AFB looking unit. Anyway, the thing wont idle at all and the rpm jumps up and down wildly at idle. It runs fine at road speed. Do you know what application this number is correct for? Any tips to make it run? Thanks!!

[Ralph Messina CLC 4937]

John,
According to The Carburetor Shop ( http://www.thecarburetorshop.com/Carbsaleapplication.htm TARGET=_blank>http://www.thecarburetorshop.com/Carbsaleapplication.htm  ) that is a correct number for a 1963 Cadillac. The other carbs used are Rochester 7023030 and Carter 3481.  It sounds like you have the correct unit but it’s in need of some work.
HTH,
Ralph

[Rhino 21150]

I typed that number into Google and found this page, among others. Apparently your engine (390?) could also use a 3177S, 3178S, 3351S, 3352S, 3480S, 3481S Carter AFB. http://www.carburetion.com/Kits/cadillac.htm TARGET=_blank>http://www.carburetion.com/Kits/cadillac.htm

[Philippe M. Ruel]

*** Anyway, the thing wont idle at all and the rpm jumps up and down wildly at idle. It runs fine at road speed.***

Sounds like air entering your intake manifold through somewhere else than the venturis (carb base, depression system, blown manifold gasket...).