As a grizzled old (ex) speed shop owner, I can assure you there’s a ton of confusion out there with regard to the repair, rebuild and tuning of Holley carburetors. Much of it is based upon a mix of misinformation and misunderstanding. Another part of it has to do with the fact Holley carburetors have been built for over 100 (!) years. And you can still get parts for Holley carburetors that were first released fifty or more years ago (that in itself is a wonderful testament to the dedication Holley has to it’s products, but I digress). That means there are tons of Holley carbs out there along with an equally large number of available parts.
Fair enough, but where do you begin with you need to buy parts for your Holley? First things first. You must ID your carburetor. All Holley carburetors are identified by their “List Number.” It’s a stamped number (not a raised cast number) or a laser-etched number located on the choke horn or the side of the carburetor body (depending the carburetor configuration).
Below the List Number is a four-digit date code. On OEM Holley carburetors, the Original Equipment Manufacturer part number may be stamped above the List Number. FYI, the choke horn is the raised area that houses the choke blade situated over the primary throttle bores. Looking at the carburetor from the front, you’ll see the List Number stamped on the top right side of the choke horn. If your carburetor is a later model competition style example it will not have a choke horn. Instead, the number will be stamped or laser etched on the side of the main carburetor body.
There are other locations for list numbers as well (for example, certain two-barrels, earlier race Dominators, modern Demon carbs and so on). The following video details exactly where to look for List Numbers on Holley carburetors:
Once you have the List Number in hand, how do you figure out which carb kit and tuning components you need for your Holley? In the days of yore, we’d simply look up the carburetor list number in one of three places: Holley’s current catalog, Holley’s Carburetor Numerical Listing Guide (Holley Part Number 36-168) or Holley’s Illustrated Parts & Specs Manual (Holley Part Number 36-51-7). You can purchase all three from the folks at Holley, but that may not be necessary.
Today, Holley has an online “Carburetor Rebuild Kit Selector”.
Go HERE to enter your List Number: https://www.holley.com/products/fuel_systems/carburetor_components/rebuild_kits/s/
You simply plug your list number into the wizard and bingo: Up comes a list of applicable parts including rebuild kits, gaskets and small parts. Some carburetors offer two different styles of kits: Renew Kits and “Trick Kits.” For racers, it should be a no-brainer. The Trick Kit, while it costs more, includes a number of tuning components you can use to dial in your specific Holley carburetor. Things like an assortment of accelerator pump cams, various sizes of discharge nozzles, multiple reusable gaskets and a complete tuning manual are included. Basically, the Trick Kit is the very first place to begin when dialing in your Holley carburetor.
As you can see, the folks at Holley have taken the pain out of determining what works and what doesn’t. Check out Holley’s kit selector. You’ll be glad you did.