Quote:
Originally Posted by tehsocks
It is a 4bbl Carb'd engine.
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I have always heard that with a 4bbl your most efficient acceleration is achieved with your primaries wide open but with the secondaries closed. Depending on the model of your carburetor this may be easy to do or you may have to practice. Some carb designs (vacuum secondaries) can be tuned to adjust the timing of secondary activation.
While I haven't ever tried (never had a 4bbl carbed vehicle of my own to play with), this makes sense in theory. During steady-state operation engines run reliably on mixtures that are stoichiometric or slightly rich. The primary jets should be tuned at that point for reliable ping-free operation. The secondaries should only open much when significant load is placed on the engine and maximum power is demanded. The secondaries should therefore be jetted larger to achieve an overall very rich mixture (12:1 or likely richer) to prevent ping and to smooth acceleration effects with a constant throttle input angle.
So assuming that you haven't re-jetted your carb your most efficient acceleration will occur when accelerating as hard as you can without opening your secondary throttle valve. If you wish to try your hand at re-jetting you could lean out your secondary jets if you can restrain yourself from demanding more power than the engine could deliver ping-free. It may also benefit such an old carb to have a rebuild as the operation of the secondary throttle valve is usually dependent on springs that weaken with age.
Also pay attention to your ignition advance, especially if it is vacuum dependent. Tuning the combination of carburetor and distributor can give you excellent performance. My uncle used to be an independent auto mechanic before the prevalence of EFI and tuned his 1970 Mercury with a 429 to get 29 mpg highway with a new distributor and freshly rebuilt carb.