Hello again just looking for some feed back on the Holley 4000 I am about to start to rebuild one but I have been told it "WILL SET MY CAR ON FIRE ' looking for some pros and cons thanks 

I have no issues with the Holley model 2140 and 4000 4V carbs on their intended applications.  The amount of detail in the construction of those carburetors is like working with a fine piece of jewelry.  Besides the throttle shafts being bronze bushed in the main body, even the shaft for the choke is bronze bushed in the model 4000 carbs.  These carburetors do work well on dual quad setups due to them being on the small side cfm wise.  If the carburetor is simply being kitted, then under no circumstances should the throttle blades be removed from the shafts.
  
One of the major deterrents of those Teapot carbs is that they are not friendly with the later model vacuum advance distributors if trying to use the vacuum advance portions of those distributors.  They are fine as built with the mechanical portion of those distributors.  The Teapot carbs do utilize both a venturi and ported vacuum signal in conjunction with a spark advance valve and that particular vacuum signal is not suited for use with the 1957 and up distributors.  That vacuum signal works great for the Load-O-Matic distributors though.  There are modifications that can be made to the carburetors’ distributor vacuum circuitry that does make those 1956 and earlier carbs compatible with the later model distributors that incorporate both mechanical and vacuum advance capabilities.  Anther issue that comes to the forefront is that the model 2140 and 4000 4V carbs are overly sensitive to using ethanol laden fuel but that’s easily compensated for with slightly richer jetting.  I find that having primary main jets two numbers richer than stock eliminates the hesitation issues created by the inclusion of ethanol in the gasoline.
 
If rebuilding the carb yourself, the power valve diaphragm can be tricky to put in place and seal so that it works as intended.  I prefer to use some white grease on both sides of the rubber part of the actuator to help seal it to the fuel bowl lid.  Depressing the actuator while tightening both the secondary jets and the single screw also helps to seat the rubber portion of the actuator so that it’s in a more relaxed position when being pulled up with vacuum.  Testing that actuator before putting the ‘lid’ on the carburetor is accomplished by depressing the spring loaded shaft while holding two fingers over the air cleaner stud hole and then holding another finger on the vacuum port hole at the front of the lid.  If the actuator shaft remains depressed when removing your finger from the actuator shaft, it’s holding a vacuum.  Taking your finger off of the front vacumm port should then have the shaft relaxing itself or going to its natural extended position.  Also keep in mind that the carburetor stud when installed in the lid does need a gasket there.  Although that air cleaner hole in the fuel bowl lid has a bushing, those are known to not seal perfectly and if there's a vacuum leak there, then the power valve will be open all the time and fuel mileage suffers accordingly.  Other than this, I know nothing about Teapot carbs.  LOL.

Lorena, Texas (South of Waco)

Thanks Ted, I always look forward to your feed back. Lots of good information 

I appreciate everyone’s feedback 

One of the Places that can Leak is the screw-on Cover for the Needle+Seat. There is a new replacement that corrects that Problem. If You keep the Teapot I would recommend You replace that Cover.

  

Reading back over all the post I can relate to everything Florida Phil wrote. I am new y blocks but have been fooling with Chrysler engines and GM for a long time . I do remember not wanting to touch the anything to do with timing fearing the engine would never run . My timing light wiring always seemed to wind up on a exhaust manifold carb return springs were made of rubber bands. Engine flush worked well until all the crud washed into the pan and starved the engine for oil. I am just rambling.

I wish I knew the tricks they used at PONY (out of business now) that made THEIR teapot rebuilds run so strong. 

6 VOLTS/POS. GRD. NW INDIANA

If you didn’t die in the carb fire you were killed when the brakes failed because of the single reservoir master cylinder....yea right.

56 Vic, B'Ville 200 MPH Club Member, So Cal.

Or you were impaled on a 1955 TBird steering wheel.   Nostalgia is great as long as it doesn't hurt you. 

I've own 3 56 Crowns, including a 64B, 3, 56 2 door victorias 1 56 a 4 door vic, and a 56 wagon, all had teapots, about 1/2 i had rebuilt, all ran great and never had a carb problem.