Here's how to determine it:
1. Visual Inspection: The easiest and most reliable method. Locate the carburetor on the engine. The carburetor itself will have identifying numbers stamped or cast into its body. These numbers are crucial for identification. Take clear pictures of all visible numbers.
2. Check the Emission Tag: Look for an emissions sticker or tag under the hood. This sticker usually contains information about the engine and emission components, which *might* include the carburetor type or a related part number. However, this is not always reliable.
3. Vehicle Identification Number (VIN) Decode: The VIN contains information about the vehicle's specifications. You can use a VIN decoder (many online services offer this) to obtain build sheet information. This *might* reveal the carburetor type, but it's not guaranteed. VIN decoding often provides general engine options, not always the specific carburetor.
4. Original Documents: If you have any original paperwork (owner's manual, build sheet, etc.) for the vehicle, it might specify the carburetor. This is the most accurate source if you have it.
Where to look for numbers on the carburetor:
The identifying numbers are usually found on a casting on the carburetor's main body. Look for a series of numbers and sometimes letters. They might be located on the top, side, or bottom of the carburetor.
Once you have the numbers:
You can use online resources like carburetor identification guides, parts websites (like Summit Racing, Jegs, etc.), or forums dedicated to classic GM vehicles to help identify the carburetor using those numbers.
In short: Visual inspection and looking for casting numbers on the carburetor itself is the most effective method. All other methods are supplementary and may not provide a definitive answer.
