Some of the most popular Corvettes ever built were the chrome-bumper cars from '56 through '72. Within that model lineup, Holley carburetors saw service from '65 through '72. In some of those model years ('67 is a good example), Holleys were used exclusively. And in the aftermarket, Holley has offered-and still offers-hundreds of different carburetors targeted at different vehicle combinations. Plenty have been retrofitted to Corvettes of all model years, too.
A majority of Holley carburetors were engineered as racing or high performance pieces. That meant they were (and still are) equipped with a number of easy-to-operate external tuning adjustments. For the performance freak, that's good news. You can easily fine-tune the carburetor to suit your application, and you can accomplish the basic tuning without going inside the carburetor. So far so good, but there's a bit of a hitch: If someone doesn't know what they're doing, they can just as easily turn a sweet running Corvette into a dud.
So which way do you turn the knobs, and which knobs do you turn? While not all of the adjustments involve actual "knobs," the basic external setup of a Holley isn't difficult. Everything can be accomplished at home with simple hand tools. For a closer look, check out the following. We're using a very common vacuum-secondary 3310 Holley as the example, and everything shown here applies to most factory installed Holleys, too.
|Difficulty Index - 2 Wrenches|
|Anyone’s Project: no tools required||1 Wrench|
|Beginner: basic tools||2 Wrenches|
|Experienced: special tools||3 Wrenches|
|Accomplished: special tools and outside help||4 Wrenches|
|Professionals Only: send this work out||5 Wrenches|
The tools you need: A vacuum gauge, a couple of flat-blade screwdrivers, a Phillips screwd
Float setup is first. There are a number of theories about the right and wrong way to adju
On the secondary side the sight plug is situated lower on the bowl. In this case, set the
To set the floats, loosen the slotted lock screw at the top of the fuel bowl, and then tur
With the float level set, you can fine-tune the accelerator pump discharge nozzle (shooter
Accelerator pump shooters are attached to the main body of the carburetor in the venturi a