Yes, 390 or 500 Holly only.

That's exactly one of my problems, I heard a hissing noise while it was idling , I put my finger exactly over the tube and the hissing stopped.
Thanks

But mine doesn't idle properly, I've decided to put on a new carb with an adapter on my current intake, replace the filter, I want to drive my car up to maybe 100 mile trips, i'm not concerned about mpg as much as I am reliability.

That's practically the same engine as in my truck!!! I 've to fix the ignition first,if it's still not running good bigger jets will be the next step.
I've no clue if in Italy fuel quality is better or worse as in California,but it's surely more expensive!!!!!!

My 292 is basically stock, just an Isky E4 cam and Pertrionix conversion. I don't recall the jet numbers but I had a slight miss at cruising speeds and went up 2 jet sizes cured it. I'm running crap California gas so that may have been part of the problem with the original jet size?

What jets do you have on the 390? Is your 292 otherwise stock?

I use a 390 on my 292, great for a non race street machine. I did have to re jet it. The 390 also has smaller diameter venturi which matches the small ports in the A & B manifolds.

Holley made a 390 CFM 4BBL and a 350CFM 2BBL. The better choice would be the 390 as the two primary throttle plates are small enough to provide good response at low
RPMs. Pete

This is what Ted is talking about.




Lawrenceville, GA

I’m not familiar with a 350 cfm Holley four barrel carb? Is this a misprint?
 
On the Holley 4V Teapot carbs, one of the major problems is getting the power economizer valve assembly to seal properly to the top cover plate.  Unless this assy is perfectly sealed, the power jet below it remains open all the time thus enriching the fuel mixture all the time rather than just when the engine is under acceleration.  There is also a brass bushing within the carb stud hole in the top cover plate and it must also be sealed to insure the vacuum signal going to the economizer valve is not lost.  A rubber washer under the air cleaner stud nut at the top of the cover plate fixes this particular problem most of the time.  The Teapot carburetor kits now come with a generic valve assembly but back in the day, those valves were specific to the application.  On certain applications, I have had to cut one or two of the coils from the top of the economizer valve spring to alter the point in the vacuum range at which it opens (or closes depending upon your perspective).  All these factors affect the fuel mileage.

Lorena, Texas (South of Waco)