Q How much fuel pressure should I run?

A The recommended fuel pressure is 6-psi, however the fuel pressure should never exceed 7-psi.  One of the biggest problem areas with carbureted applications is excess fuel pressure. This causes the low speed to be too rich when you adjust the needle and seat down (to prevent flooding), whereas the float drop is reduced, which in turn, prevents the needle from opening completely. That scenario could potentially cause a high-speed lean out.  Please note: This answer relates to mechanical or electric fuels pumps only.  Belt driven mechanical pumps (typically used with methanol) have two pressure stages, low and high rpm.

Q How do I know when my idle is right?

A There are a lot of considerations for a quality idle, but some of the basics are:
The engine should be a little cold blooded, that is, it will not idle very well when the engine is cold.  In other words the engine should only idle on its own after it has run for a few minutes to build some heat. The engine should return to the same idle speed consistently, though. Long duration camshafts on racing applications generally have to be slightly richer, as opposed to adjusting the idle on a street engine. With a high-rpm racing torque converter the idle speed should only fall off a couple hundred rpm when shifted into gear.

Q How do I determine the best jet size for my carburetor?

A Best jetting is usually established by changing jet size to achieve the highest mph.  Mile per hour has a direct correlation to peak engine horsepower.  This simply means that you test different jet sizes with your combination (according to the present weather conditions) to find where it makes the best power.

Q What is the advantage of annular boosters and why would I want to use a carburetor equipped with them?
 
A Annular boosters provide a broader operating band over conventional boosters.  In applications where the functional operating range is extremely wide, these boosters amplify the available signal (air velocity) and effectively increase the average power through a broad operating range.

Q I have problems getting the engine to come up in rpm with a trans brake. What do I need to change in the carburetor to fix this?

A Getting the engine to come up on the chip can be difficult, especially when you attempt to go wide open from idle. If the carburetor is sized to produce the best engine power, its efficiency is less than optimum at lower rpm. It often takes a lot of extra fuel to help make this transition. More accelerator pump shot (bigger squirters) and a slightly richer idle mixture screw setting will help the engine free rev from an idle to the converter flash point (or the chipped rpm setting) by providing extra fuel to make up for the big surge of air going into the engine when you first go wide open throttle from a dead idle.

Q Is ignition timing a big issue when dialing in a carburetor?

A Ignition timing, especially the initial timing, is crucial to enable the carburetor to work correctly.  With today's camshaft profiles, it is difficult (if not impossible) to get the engine to respond properly if the timing is not locked out, that is set at the maximum timing once the engine starts. Applications that use a distributor mechanical advance, where the initial timing is set relatively low, relying on distributor advance weights to achieve maximum timing, makes it extremely difficult to flash the converter on the starting line with a trans brake. Lack of timing at the initial hit of the throttle makes it almost impossible to get enough fuel through the carburetor for the engine to rev up against a load without a bog or hesitation.  DR