1981 Chevrolet Trucks K20 Tires

The 1981 Chevrolet Trucks K20 uses either 8.75R16.5 or 950-16.5, depending on the exact sub-model. The 6800 GVWR versions use 8.75R16.5 radial tires, while the 8600 GVWR front and rear applications use 950-16.5 bias-ply tires.

The important step is matching the truck’s exact configuration before choosing a replacement tire. A K20 that has had wheel, axle, or suspension changes over the years should be checked carefully so the actual wheel diameter, tire construction, and service setup still match the size being considered.

Both primary tire sizes used on the 1981 Chevrolet Trucks K20 are built for a 16.5-inch rim. That applies to the 8.75R16.5 radial fitment and the 950-16.5 bias-ply fitment, even though the truck can use more than one tire size depending on its sub-model.

Wheel diameter is only part of the fitment picture, so it still makes sense to confirm the actual wheel on the truck before replacing tires. Many older trucks have been changed over time, and a 16.5-inch wheel must also be paired with the correct tire width range and the intended K20 load-class setup.

The 1981 Chevrolet Trucks K20 has more than one tire size because fitment changes with the truck’s configuration. The 6800 GVWR sub-models use an 8.75R16.5 radial tire, while the 8600 GVWR front and rear applications use a 950-16.5 bias-ply tire.

That means the buyer should not select a tire by model name alone. The full sub-model description, including GVWR grouping and whether the truck is one of the front or rear 8600 applications, matters before comparing tires or deciding whether the truck should stay with its original-style construction.

For the 1981 Chevrolet Trucks K20, 950-16.5 is a bias-ply tire size. It is used on the 8600 GVWR front and rear applications, while the separate 8.75R16.5 fitment is the radial size used on certain 6800 GVWR configurations.

That distinction matters because the two sizes are tied to different K20 setups, not simply two interchangeable constructions. Anyone comparing them should first verify the truck’s exact sub-model and wheel arrangement, then make sure the replacement tire matches the intended service type and the 16.5-inch wheel dimensions.

On the 1981 Chevrolet Trucks K20, 8.75R16.5 is a radial tire size. It appears on the 6800 GVWR sub-models, while the heavier 8600 GVWR front and rear applications use the different 950-16.5 bias-ply size.

This is not just a matter of choosing one construction over another within the same fitment. The size itself changes with the truck’s configuration, so the right approach is to confirm the exact K20 setup first, then verify wheel diameter and overall compatibility before moving ahead with a replacement.

The correct answer depends on which 1981 Chevrolet Trucks K20 configuration is being fitted. Certain 6800 GVWR versions use 8.75R16.5 radial tires, while the 8600 GVWR front and rear applications use 950-16.5 bias-ply tires, so the truck’s intended fitment determines the construction choice.

A restoration-minded owner may want to stay with the construction tied to the truck’s original setup, while a working or regularly driven truck still needs the right size and wheel match first. Construction choice should follow confirmed sub-model fitment, not override it, especially on a heavy-duty 16.5-inch wheel application.

Start with the truck’s exact application, because 950-16.5 belongs to the 8600 GVWR front and rear K20 setups. Within that size, available tires are bias-ply blackwall truck designs from STA, and both carry a 2780@60 psi maximum load capacity on a 16.5-inch rim.

From there, compare the tire series and make sure the wheel width matches the stated 6.50 to 6.75 inch range. It also helps to think about how the truck will be used, since a restoration-focused K20 and a regularly driven heavy-duty pickup may lead an owner to favor one series character over another.

For the 950-16.5 fitment used on certain 1981 Chevrolet Trucks K20 applications, the available tires come from STA. Those options are both bias-ply truck tires in blackwall form and are offered in the Traxion and Super Transport series.

Brand is only one part of the decision, especially on an older heavy-duty truck. After confirming the exact K20 sub-model, it makes sense to compare the tire series, rim-width compatibility, and service-oriented character of each option so the replacement matches the truck’s actual use and wheel setup.

The 950-16.5 fitment for the 1981 Chevrolet Trucks K20 is available in two STA series: Traxion and Super Transport. Both are bias-ply blackwall truck tires built for 16.5-inch rims and aimed at heavier-duty pickup use.

Series differences can matter when the size and construction stay the same, because they shape the overall character of the tire selection. A buyer should still begin with the correct K20 fitment first, then compare the series alongside rim-width requirements and the truck’s intended driving or work use.

A period-style 1981 Chevrolet Trucks K20 should begin with the tire size and construction that match its exact sub-model. That means 8.75R16.5 radial for the 6800 GVWR configurations and 950-16.5 bias-ply for the 8600 GVWR front and rear applications.

Once the fitment is correct, appearance becomes more meaningful because the tire supports the truck’s overall stance and working-truck character. Owners chasing exact restoration accuracy should compare their truck against build records, marque references, or other vehicle-specific documentation before treating any one tire as an originality claim.

Tire construction can change the visual impression of a restored 1981 Chevrolet Trucks K20 because radial and bias-ply tires do not present the same way on the truck. On this model, construction also follows fitment, with 8.75R16.5 used as a radial size and 950-16.5 used as a bias-ply size on different configurations.

That makes appearance and fitment closely related rather than separate decisions. A truck restored for factory-era character usually benefits from starting with the proper size and construction for its sub-model, then evaluating sidewall style and tire series within that framework instead of choosing by looks alone.

Yes, modifications can affect tire fitment on a 1981 Chevrolet Trucks K20. Aftermarket wheels, suspension changes, altered ride height, brake conversions, or axle changes can all affect whether the truck still matches its original 16.5-inch tire and wheel setup.

That is especially important on a K20 because the correct tire size already varies by configuration. A truck that has been modified should be checked for actual wheel diameter, wheel width, and clearance at the suspension and body before replacing tires, even when the owner intends to stay with the original style of fitment.

Before driving a 1981 Chevrolet Trucks K20 on new tires, inspect the wheels for correct diameter and condition, make sure lug hardware matches the truck, and confirm the tires are inflated appropriately for their service use. It also helps to check steering and suspension components for looseness or wear.

A short test drive should include attention to rubbing, unusual vibration, or uneven tracking, especially on an older truck with heavy-duty running gear. Any K20 that has sat for long periods deserves an additional look at wheel condition, brake function, and general chassis readiness before regular road use resumes.

950-16.5 tires on a collector 1981 Chevrolet Trucks K20 should be kept properly inflated, inspected regularly for cracking, bulges, cuts, and uneven wear, and protected from long exposure to heat, sunlight, and moisture during storage. Older collector trucks also benefit from periodic movement to avoid long static loading in one position.

Routine checks matter even more when the truck is driven infrequently, because age and storage conditions can affect a tire long before the tread is worn out. It is wise to inspect the wheel and valve area for air loss as well, then reassess the whole setup before any longer drive or hauling duty.