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Old 07-25-2003, 06:22 PM
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4 Jaw Chuck 4 Jaw Chuck is offline
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Let me try to answer your thoughts;

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There is better fuel metering through annular boosters in general
Absolutely correct, except the reason why they put annular boosters on the two barrels is because they start "signalling" at lower velocities and with the big holes you need them. Any Holley booster can be retrofitted to any Holley carb by removing your old booster and "spinning" in the type you prefer (you slide hammer out the old ones). It is very involved to accomplish and for the street will likely have no effect on performance although metering will improve slightly. Their main benefit is better metering at low air velocities so mileage/economy would be the only gain you see.

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It is one less throttle shaft, therefore less vacuum leakage.
Not even enough to worry about as long as the carb is in good condition.

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Only having "primaries" and no "secondaries" to tune would be a lot easier, especially tuning by "the seat of your pants feel".
Having multiple stages to tune can seem a little harder but not compared to trying to get a big holed two barrel to meter efficiently at low speeds, tune with your stopwatch not your butt. Eliminating the secondaries means your foot becomes the bog sensor and you will have to drive it that way...much like a double pumper.

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There is less chance of fuel leaks with two barrels.
Half as many bowls...can't argue with that. But if Holleys are rebuilt properly with the good gaskets they don't leak any more than an identical two barrel.

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I have about ten different Holley four barrels in my garage, and I am trying to thin them out
Please send all unwanted 750 Double pumpers my way please, condition is unimportant. You can scrap the rest. It sounds to me like what you want/need is a nice 3310 squarebore 750 double pumper, still the best carb they ever made if you ask me. The 780 vacuum secondary is good too but good luck finding one. Most guys here swear by the Demon carb, I have never had one so I cannot comment on them but from what I have heard/read they are the best Holley carb never made by Holley.
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