1982–1984 Models
| D | Inline-6, 250 ci |
| T | Inline-6, 292 ci |
| H | V-8, 305 ci |
| L | V-8, 350 ci |
| M | V-8, 350 ci, Heavy Duty |
| C | V-8, 6.2, Diesel |
| J | V-8, 6.2, Diesel |
| W | V-8, 454 ci |
1985–1986 Models
| T | Inline-6, 292 ci |
| N | V-6, 262 ci |
| H | V-8, 305 ci |
| L | V-8, 350 ci |
| M | V-8, 350 ci, Heavy Duty |
| C | V-8, 6.2, Diesel |
| J | V-8, 6.2, Diesel |
| W | V-8, 454 ci |
1987 Model
| T | Inline-6, 292 ci |
| Z | V-6, 262 ci, Throttle Body Injection |
| H | V-8, 305 ci, Throttle Body Injection |
| K | V-8, 350 ci, Throttle Body Injection |
| C | V-8, 6.2, Diesel |
| J | V-8, 6.2, Diesel |
| W | V-8, 454 ci, 4-barrel carburetor |
| N | V-8, 454 ci, Throttle Body Injection |
Ninth Digit: Check Digit
Tenth Digit: Model Year
| B | 1981 |
| C | 1982 |
| D | 1983 |
| E | 1984 |
| F | 1985 |
| G | 1986 |
| H | 1987 |
| J | 1988 |
| K | 1989 |
Eleventh Digit: Assembly Plant
| F | Flint |
| J | Janesville |
| S | St. Louis |
| Z | Freemont |
| 1 | Oshawa |
Remaining Digits
The remaining digits are a sequential serial number, unique to the truck.
The VIN is located in a few different spots, depending on the year of the truck. There’s the aforementioned doorjamb plate for pre–1978 models and the plate on the dashboard for 1979–1987 models.
If the dashboard is intact, you can also find a factory options decal located in the glove box. This should help you determine the trim level of the truck.
Once you know the VIN, the next step is to decode the information according to the various generations and designations.
The easiest way to find out if you have a fake is to start with either the sixth (1973–1980) or tenth (1981–1987) digit in the VIN. This tells you the year of the truck, and it’s something you can compare against what the owner tells you.
In addition, you can check for VIN locations in other spots on the truck to ensure that all of them match. Compare the glove box number with the one on the dashboard, for example, or the one on the frame (underneath the cab on the passenger side between the mounting holes for the forward bed bolts). There is also a VIN stamped on the engine block and transmission, but if the truck is either missing the drivetrain or it has been swapped, you’re out of luck.
The more factory parts and stickers present on the truck, the more valuable it is. This truck had all of the factory stickers in the correct spots. In addition, the original jack and tire iron were still in the fenderwell.
The next thing to look for is sheet-metal changes. As previously mentioned, some eras of front clips are preferred to others, and it changes based on taste. It’s entirely likely that you find a 1981–1987 truck with 1973–1980 front fenders, hood, and grille because that was the owner’s favorite style. But what’s also common is the wrong grille on a specific year.
Another general rule is to gently knock on the metal with your knuckles, listening for differences in tone. If body filler was used, the sound tends to sound much less hollow than metal without bodywork. You can also look inside the fenders and under the hood for paint overspray or dents, both of which indicate either replacement or previous bodywork. Pay particular attention to the area around the lower bed sides on the earlier trucks, as they could have been replaced at some point as well.
Let’s say that you find a truck online that you like and go to check it out. The owner tells you it’s a 1981 Chevrolet Silverado with the 6.2 diesel. When you look closely, you see that the turn-signal lenses are in the grille, not the bumper, which tells you that it’s at least a 1983. Now that your suspicion is raised, you remember that the 6.2 diesel engine wasn’t introduced until 1982, so the truck can’t be a 1981.
What you do with that information is up to you. If you prefer what the year actually is versus what they’re telling you, you can proceed. Just be sure that the title or paperwork for the truck indicates the correct year and model; otherwise, you could be purchasing a stolen truck or one with fouled paperwork.