vetteman061

Hello everyone,

My dad has a '61 Vette with a 327 and a 4 Jet carb, manual transmission with no power options. It has never run correctly and I'm going to try to figure out why. First step: I'd like to make sure the vacuum advance is correct. The car has a Rochester 4Jet and I want to make sure the location for the vacuum advance is non-ported so that it will have advance at idle. I am aware that the choke tube is broken. I couldn't find any casting numbers and the stampings I saw said Patent Applied For.

The vacuum advance is hooked to the back, middle of the carb. I believe this is non-ported. Is this correct?

Every other vacuum port is blocked off. Could anyone tell me any other information by the numbers on the intake?

Thanks,

plaidside

That carburetor was used on my early GM engines in passenger cars and trucks. I do not believe it was used in any Corvette.
It is a very reliable carburetor and there was no ported vacuum ports IIRC.
You have full manifold vacuum using that port.
The were no numbers on these carburetors on a triangular brass tag with the OE number stamped in it.
Joe

vetteman061

Thank you for the reply.

Aside from other issues, do you believe this carburetor may be too small for a 327, .60 over with a performance cam of unknown grind but does have a small lope to it?

Thanks,

W Guy

Well, it's mounted on a 283 intake manifold so the carb is probably for a 283 with the smaller throttle bores to match. You'd be able to drive around ok with it as is, but it probably won't perform very well with a worked over 327. To take advantage of the engine size and hi-po cam, you'd need to change both the intake and carb to match that engine.
A set up from a 300hp with an AFB would be best.

Verne

vetteman061

Thanks for the response and info, I appreciate it.