The 1981 GMC Trucks K3500 came from a period when one-ton 4x4 pickups were expected to work hard, carry serious weight, and handle rough service without unnecessary frills. For owners restoring one for utility, preservation, or regular vintage truck use, tire choice is closely tied to that heavy-duty character. This K3500 uses bias-ply fitments in 750-16, 875-16.5, and 950-16.5, so the first step is confirming the exact wheel diameter and sub-model setup. Available choices range from traditional blackwall truck tires to highway, traction, military-style, and whitewall offerings in certain sizes. Getting the right size and construction matters just as much as matching the truck's intended appearance and use.
Which Tire Size Is Right for The 1981 GMC Trucks K3500
Three primary tire sizes apply to the 1981 GMC Trucks K3500, and the correct choice depends on the exact sub-model and wheel diameter. Some K3500 configurations use 16-inch wheels while others use 16.5-inch wheels, so wheel confirmation comes first. Once that is settled, the next decision is choosing the right bias-ply tire style for the truck's intended use, whether that means a traditional highway pattern, a traction-oriented tread, or a more restoration-minded appearance.
Fit(s): (7/16 & 1/2 inch studs)(GVWR 10000) and (9/16 inch studs)(GVWR 10000)
Construction: Bias Ply|Rim: 16 in
The 750-16 size uses a vintage numeric bias-ply format, where 7.50 refers to the nominal section width in inches and 16 identifies the wheel diameter. On the 1981 GMC Trucks K3500, this is a bias-ply truck fitment that suits owners keeping the truck in a traditional heavy-duty tire construction. Product choices in this size are especially broad, including Firestone, Lester, BFGoodrich, and STA options with blackwall, wide whitewall, military-style, highway, and traction-oriented series. It is a useful size to evaluate carefully if your K3500 is built around a 16-inch wheel and you want the widest range of period-style tire choices.
Fit(s): (7/16 & 1/2 inch studs)(GVWR 10000) and (9/16 inch studs)(GVWR 10000)
Construction: Bias Ply|Rim: 16.5 in
The 875-16.5 size is also a vintage numeric bias-ply designation, with 8.75 indicating nominal section width and 16.5 indicating the required wheel diameter. For the 1981 GMC Trucks K3500, this size keeps the truck in a traditional bias-ply construction and belongs to configurations using a 16.5-inch wheel. Available choices center on STA truck tires, with blackwall options in both Traxion and Transport Highway series. This size makes sense to review when the truck's wheel setup calls for a 16.5-inch tire and the goal is a straightforward heavy-duty truck presentation rather than passenger-car styling.
Fit(s): (7/16 & 1/2 inch studs)(GVWR 10000), (7/16 & 1/2 inch studs)(GVWR 9200) Front, (7/16 & 1/2 inch studs)(GVWR 9200) Rear, (9/16 inch studs)(GVWR 10000), (9/16 inch studs)(GVWR 9200) Front, and (9/16 inch studs)(GVWR 9200) Rear
Construction: Bias Ply|Rim: 16.5 in
The 950-16.5 designation follows the same numeric bias-ply system, pairing a nominal 9.50-inch section width with a 16.5-inch wheel diameter. On the 1981 GMC Trucks K3500, this size appears on certain heavier-duty configurations and stays true to the truck's original bias-ply replacement character. STA offers blackwall choices in Traxion and Super Transport series, with both options carrying a truck-focused specification and a 6.50 to 6.75 inch rim-width requirement. This is the size to examine when your K3500 uses the larger 16.5-inch wheel setup and tire load support and wheel compatibility are central concerns.
Sub-model fitment on the 1981 GMC Trucks K3500 is not one-size-fits-all. Stud size, GVWR rating, and whether the listing is for the full vehicle or the 9200 GVWR front and rear positions all affect which tire size belongs on the truck, so identifying the exact configuration is essential before choosing a tire.
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1981 GMC Trucks K3500 (7/16 & 1/2 inch studs)(GVWR 10000)
This 10000 GVWR configuration can use 750-16, 875-16.5, or 950-16.5 bias-ply tires depending on the wheel setup. The important next step is confirming whether the truck has 16-inch or 16.5-inch wheels before comparing tread style, sidewall presentation, or truck-duty tire series.
1981 GMC Trucks K3500 (7/16 & 1/2 inch studs)(GVWR 9200) Front
This front-position 9200 GVWR configuration uses the 950-16.5 bias-ply size. Tire selection is more straightforward here, but the truck still needs the correct 16.5-inch wheel and enough attention to rim width and overall setup before moving ahead with a replacement.
This rear-position 9200 GVWR configuration also uses the 950-16.5 bias-ply size. That means the focus shifts away from choosing among multiple primary sizes and toward selecting the right truck-oriented tread and confirming that the wheel matches the tire's 16.5-inch fitment requirements.
1981 GMC Trucks K3500 (9/16 inch studs)(GVWR 10000)
This 10000 GVWR setup with 9/16 inch studs can use 750-16, 875-16.5, or 950-16.5 bias-ply tires. Because more than one rim diameter is involved, the safest starting point is checking the actual wheel size on the truck before narrowing the choice to a specific series or use pattern.
1981 GMC Trucks K3500 (9/16 inch studs)(GVWR 9200) Front
This 9200 GVWR front application uses the 950-16.5 bias-ply tire size. With the size already narrowed down, the practical decision becomes choosing between the available truck tire series and making sure the wheel and rim-width setup are appropriate for that 16.5-inch tire.
1981 GMC Trucks K3500 (9/16 inch studs)(GVWR 9200) Rear
This 9200 GVWR rear application uses the same 950-16.5 bias-ply fitment. Buyers comparing tires here should focus on the truck's actual wheel specifications and whether a highway-style or more traction-oriented tread better matches how the K3500 will be used.
The tire sizes listed on this page assume factory-standard vehicle configuration. The following modifications may affect tire fitment and are not reflected in this guide:
Suspension changes (lowering, lift kits, spring replacements)
Body alterations (fender modifications, custom bodywork)
If your vehicle has been modified from factory specifications, verify tire clearance before purchase.
Best 1981 GMC Trucks K3500 Tires for Sale
Available 1981 GMC Trucks K3500 tires center on bias-ply truck fitments, with Firestone, Lester, BFGoodrich, and STA options depending on size. Choices vary by tire series, blackwall or wide whitewall presentation in 750-16, and more work-oriented highway, transport, traction, or military-style patterns.
These FAQs focus on the real tire decisions for a 1981 GMC Trucks K3500, including size selection by sub-model, 16 versus 16.5-inch wheel fitment, bias-ply construction, restoration-minded appearance, and the checks worth making before road use.
Tire Size & Fitment
What tire size fits a 1981 GMC Trucks K3500?
The 1981 GMC Trucks K3500 uses three primary bias-ply tire sizes: 750-16, 875-16.5, and 950-16.5. The correct one depends on the truck's exact sub-model, GVWR configuration, and wheel setup. Some 10000 GVWR applications can use more than one size, while the 9200 GVWR front and rear applications use 950-16.5.
The first thing to verify is whether the truck has 16-inch or 16.5-inch wheels, because those diameters are not interchangeable. After that, match the tire size to the exact K3500 configuration and compare the intended tread style, rim-width requirements where applicable, and how the truck will actually be used.
What size rim does a 1981 GMC Trucks K3500 use?
A 1981 GMC Trucks K3500 can use either a 16-inch rim or a 16.5-inch rim, depending on the tire size and configuration. The 750-16 tire belongs on a 16-inch wheel, while both 875-16.5 and 950-16.5 require a 16.5-inch wheel. That split is one of the most important fitment details on this truck.
Checking the actual wheel on the truck matters more than assuming all K3500s use the same rim diameter. A truck that has had wheels changed over the years may no longer match its original setup, so confirm the wheel size before selecting a tire and then compare wheel width where the tire specification makes that relevant.
Why does the 1981 GMC Trucks K3500 have more than one tire size?
More than one tire size applies because the 1981 GMC Trucks K3500 was offered in different heavy-duty configurations. Stud size, GVWR rating, and front or rear application within the 9200 GVWR setup all affect which primary bias-ply tire size belongs on the truck. That is why 750-16, 875-16.5, and 950-16.5 all appear within the K3500 range.
For a buyer, that means the nameplate alone is not enough to choose a tire. The practical next step is identifying the exact sub-model and confirming whether the truck is on 16-inch or 16.5-inch wheels, since that determines which tire family should even be considered before tread pattern or appearance enters the decision.
Choosing the Right Tire
What should I consider when choosing a 1981 GMC Trucks K3500 tire?
Start with the correct primary size for the truck's exact configuration, then confirm the wheel diameter and construction type. The 1981 GMC Trucks K3500 uses bias-ply fitments, so the next layer of selection is whether the truck needs a more traditional passenger-style presentation in 750-16 or a more work-oriented truck tire in 750-16, 875-16.5, or 950-16.5.
After size and wheel match are settled, compare tire series, sidewall style, and any rim-width or load specifications that apply to the size you need. A truck headed to shows may call for a different look than one used for utility driving, and that difference often matters just as much as the size itself.
What sidewall styles are available for 1981 GMC Trucks K3500 tires?
Sidewall style depends on the tire size. In 750-16, blackwall and wide whitewall options are available, which gives that size a broader appearance range. The 875-16.5 and 950-16.5 sizes are centered on blackwall truck tires, which suits the K3500's heavy-duty character and utility-focused presentation.
That means appearance choice is much wider if the truck uses 750-16 on a 16-inch wheel. Owners restoring a work-truck look will usually stay with blackwalls, while a more styled vintage presentation may point toward a wide whitewall in that size, provided it still matches the truck's wheel and intended use.
What brands offer tires for the 1981 GMC Trucks K3500?
Brand availability varies by size on the 1981 GMC Trucks K3500. The 750-16 size includes Firestone, Lester, BFGoodrich, and STA choices, while the 875-16.5 and 950-16.5 sizes are represented by STA. That makes the 16-inch fitment the broadest area for comparing both appearance and series differences across brands.
The most useful way to compare brands on this truck is not by reputation alone, but by what each size actually offers. One size may give you whitewall and classic-style choices, while another is focused almost entirely on truck-duty blackwall tread patterns, so the brand decision follows the size and wheel decision.
Restoration & Appearance
Which tire should I choose for a period-style 1981 GMC Trucks K3500?
A period-style choice starts with using the correct primary size and staying with the truck's bias-ply construction. For a 1981 GMC Trucks K3500 on 16-inch wheels, 750-16 offers the broadest visual range, including blackwall and wide whitewall options. The 16.5-inch sizes lean more heavily toward work-oriented blackwall truck tires.
That usually means the truck's intended personality guides the final decision. A restoration centered on utility and heavy-duty character may look most natural with a highway, transport, or traction-style blackwall, while a more presentation-focused build may benefit from one of the whitewall offerings available in 750-16.
Does correct tire fitment matter for a 1981 GMC Trucks K3500 restoration?
Correct tire fitment matters because it affects both the truck's stance and its functional character. The 1981 GMC Trucks K3500 spans multiple primary sizes and two rim diameters, so using the wrong combination can change the truck's appearance and move it away from the configuration you are trying to preserve or recreate.
A restoration-minded buyer should verify the exact sub-model, wheel diameter, and overall visual goal before choosing among available tires. When originality matters beyond general period style, it is smart to compare the truck against marque references, surviving examples, or build-specific documentation rather than relying on size alone.
Fitment, Maintenance & Road Use
Can modifications affect tire fitment on a 1981 GMC Trucks K3500?
Yes, modifications can affect tire fitment on a 1981 GMC Trucks K3500. Wheel swaps, suspension changes, altered ride height, and brake conversions can all change the relationship between the tire, the rim, and the available space around the truck. That matters even more here because the K3500 uses both 16-inch and 16.5-inch wheel-based fitments.
A truck that no longer has its original wheels should be measured rather than assumed to match its original configuration. Check wheel diameter, width, and clearance at the fenders and steering components before choosing a replacement tire, especially if the truck has been rebuilt for a purpose different from its original heavy-duty setup.
What should I inspect before driving a 1981 GMC Trucks K3500 on new tires?
Before driving a 1981 GMC Trucks K3500 on new tires, inspect the wheels for correct diameter and condition, make sure the lug hardware matches the truck's stud setup, and confirm that the tires are seated properly. It also helps to check overall clearance with the suspension at rest and with the steering turned where applicable.
The truck itself deserves the same attention as the tires. Look over steering components, suspension wear points, brake condition, and inflation pressure before heading onto the road, because an older one-ton 4x4 can put serious demand on every part of the running gear once fresh tires are installed.
How should 1981 GMC Trucks K3500 tires be maintained on a collector truck?
Collector-truck tires should be kept properly inflated, inspected regularly, and protected from long periods of heat, sunlight, and ozone exposure. On a 1981 GMC Trucks K3500, that is especially important because bias-ply truck tires may spend long stretches parked before being asked to carry real weight again.
Regular inspections should include looking for sidewall cracking, bulges, cuts, uneven wear, and slow air loss. Even a truck that sees only occasional use should have its tires checked before each outing, since age, storage conditions, and long stationary periods can affect tire condition as much as road mileage.
