Bud - Holley or BG, those jets sound way too rich. It's possible the carb you received got in the wrong box at shipping.
If you turn the carb up side down and look into the venturi, the small round holes, near the base of the carb, are the idle circuit vacuum feeds. With the butterflies closed at idle, engine vacuum draws air/fuel mixture from the idle circuit. Higher in the venturi you will see the slots. They are the vacuum draw for the transfer circuit. This circuit provides additional air/fuel as you make the transfer from idle circuit to main jet circuit.
Stock engines have loads of vacuum at idle. Butterflies can be almost entirely shut and the engine will idle, and idle richness adjustments can be made properly with the needle screws. High performance engines with overlap cams have very low vacuum at idle, simply because the intake and exhaust valves are open at the same time. Often, to make the car run at all, you have to open the primary butterflies so much that the butterfly exposes too much of the transfer slot and causes problems. One, since you are now running off of the idle and transfer circuits, idle adjustments you make at the needle screws have little or no effect on idle mixture, therefore you cannot get the correct idle mixture. To rich is the problem. Two, since you are using the transfer and idle circuits for idle, movement into the main jet circuit occurs too quick and all kinds of stumbling and bogging things begin to happen. Again, usually too rich. Engine stumbles, fumes burn your eyes, and the overload of fuel dumping into the engine washes
oil from your cylinder walls, and further pollutes and breaks down your
oil.
One cure for the idle problem is to open the secondary butterflies to allow more air into the engine so it will idle. To make this adjustment you have to have the carb off of the manifold. Turn the carb up side down and you can adjust the small screw in the base of the carb to open your secondary a small amount. This is where the square issue comes in. Adjust both primary and secondary butterflies so the amount of the transfer slot you can see from the bottom of the carb, appears to be square, not rectangular. This adjustment will give you more air at idle, without the need to open the primary so far you expose too much of the transfer slot. Another cure, is to drill small holes in the butterflies to allow more air to be drawn into the engine for idle purposes. Usually, you can get enough air with the secondary butterfly adjustment to cure the problem. Drilling butterflies should be done by someone with carb knowledge.
Most high performance engines do not have enough vacuum below 1,000 rpm for your carb to work correctly, or for you to be able to make correct adjustments. My 460 needs to idle at 1,050 rpm to make 8.5 inches of vacuum. Below 900 rpm the engine will hardly run at all, i.e., no vacuum.
Holley, and/or BG will tell you to run a power valve in the primary. If you do not, the lean condition that occurs between idle and main jet circuit can/will damage your engine, not to mention performance loss. Example, if you have 9 inches vacuum at idle, you need a PV several numbers lower. I run a 5.5 in my 460. As you accelerate, vacuum drops into the opening range of the PV, giving you additional mixture to prevent a lean condition until the main jet circuit takes over. If Holley or BG recommended blocking the primary PV, they would ship them this way.
Out of the box carbs can have a PV rated too high. 6.5 is usually what they come with. If your idle vacuum is too near the same number, the PV can open or fluctuate and flood your engine. If the PV is blown, fuel will constantly be supplied. This may have contributed to Gerry's problems.
Have said too much. Hope I have given you some food for thought. If you are not comfortable making adjustments, you will be way ahead to go to someone who knows exactly what to do. If your carb is off, performance is nil, and all the stumbling and bogging makes the car no fun to drive.
Lynn
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