1978 Ford F-350 Tires

The 1978 Ford F-350 does not use one universal tire size across every configuration. Primary fitments include 800-16.5, 875-16.5, and 950-16.5 bias-ply sizes, plus 8.75R16.5 radial on certain GVWR-rated versions. Dual-rear-wheel, wheelbase, GVWR, and front-versus-rear position can all affect which size belongs on the truck.

The most important step is matching the tire to the truck’s exact configuration rather than relying on the model name alone. Checking the existing tire size, confirming the 16.5-inch wheel, and noting whether the truck is a dual-rear-wheel model or a position-specific application will narrow the choice quickly and prevent confusion between similar heavy-duty fitments.

The tire fitments covered for the 1978 Ford F-350 use a 16.5-inch rim diameter. That applies across the listed primary sizes, including 800-16.5, 875-16.5, 950-16.5, and 8.75R16.5. The size code itself reflects that rim diameter, whether the tire is bias-ply or radial.

Rim diameter is only part of the wheel check. Some products also carry size-specific rim-width guidance, such as 6.00 to 6.50 inches for certain 800-16.5 tires and 6.50 to 6.75 inches for certain 950-16.5 tires, so confirming both diameter and width is a smart step before mounting new truck tires.

Multiple tire sizes appear because the 1978 Ford F-350 was offered in different GVWR ratings, wheelbases, and dual-rear-wheel configurations, with some fitments also separated by front or rear position. That is why sizes such as 800-16.5, 875-16.5, 950-16.5, and 8.75R16.5 can all be correct depending on the exact truck.

That variation means tire selection starts with the truck’s specific configuration, not with a broad year-make-model search alone. Looking at the vehicle’s current tires, wheel setup, and axle application is especially important on older work trucks, since many have seen wheel changes, mixed tire replacements, or long service lives that can blur the original fitment pattern.

The 8.75R16.5 size is a radial tire size for the 1978 Ford F-350. The R in the size designation indicates radial construction, which separates it from the truck’s numeric bias-ply sizes such as 800-16.5, 875-16.5, and 950-16.5. It appears on certain GVWR-rated versions rather than across every F-350 configuration.

Construction matters because a truck set up for one tire type should not be changed casually just because another size appears elsewhere in the model range. A careful check of the truck’s current wheel width, existing tire size, and overall clearance is the right next step before treating 8.75R16.5 as the correct choice for any specific F-350.

Both bias-ply and radial constructions appear on the 1978 Ford F-350, but they do not serve as a universal either-or choice across every configuration. Bias-ply sizes include 800-16.5, 875-16.5, and 950-16.5, while 8.75R16.5 is the radial fitment shown on certain versions. The right starting point is the exact size and construction tied to the truck’s configuration.

Bias-ply often suits an owner who wants a traditional heavy-duty truck presentation, while a radial application may appeal when the truck already uses that construction. The practical decision comes down to wheel compatibility, intended use, and whether the truck is being kept close to its period setup or being evaluated around its present tire and wheel arrangement.

A conversion should begin with the truck’s actual wheel size and current application, because the 1978 Ford F-350 includes both bias-ply and radial fitments but not as universal substitutes. Confirm the exact 16.5-inch wheel, the wheel width, the tire size already on the truck, and whether the application is tied to a particular GVWR, axle position, or dual-rear-wheel setup.

Clearance around suspension, steering, and bodywork also deserves attention before any construction change. Older work trucks are often modified or repaired over time, so a truck that once matched one specification may now have different wheels or mixed axle components. A careful inspection helps separate a true radial application from a size that simply shares the same rim diameter.

Start with the exact tire size and construction that match the truck’s configuration. A 1978 Ford F-350 may call for 800-16.5, 875-16.5, or 950-16.5 bias-ply tires, or 8.75R16.5 radial on certain versions, so GVWR, wheelbase, dual-rear-wheel status, and axle position all matter before comparing products.

Once the fitment is confirmed, the useful comparisons are tread series, rim-width guidance where stated, and product details such as truck-oriented construction and load-minded specifications. Owners restoring a period-style work truck may focus on traditional appearance, while owners preparing a truck for regular road use may put more emphasis on matching the current wheel-and-tire setup carefully.

The available tires for the 1978 Ford F-350 are from STA. That brand appears across the covered heavy-duty sizes, including 800-16.5, 875-16.5, and 950-16.5, with truck-oriented offerings in different series rather than a mix of several brands competing in the same fitment range.

Because the brand selection is concentrated, the more meaningful choice is usually between STA tire series and the exact size required for the truck. A buyer should compare the size first, then review series character, sidewall presentation, and any stated rim-width or load-capacity details that apply to the specific heavy-duty fitment under consideration.

Available tire series for the 1978 Ford F-350 include STA Traxion, STA Super Transport, and STA Transport Highway, depending on size. Those series appear across the covered 16.5-inch truck fitments, with some sizes offering two series choices and others narrowing the selection based on the exact application.

Series selection becomes useful after the correct size is established. A truck kept for restoration-oriented display may lead the buyer toward one tread character, while a regularly driven work truck may point toward another, but either way the comparison should stay inside the confirmed fitment rather than using series preference to justify a different tire size.

A period-style 1978 Ford F-350 usually starts with the exact primary size that matches the truck’s original-type configuration, whether that is 800-16.5, 875-16.5, or 950-16.5 bias-ply, or 8.75R16.5 radial on certain versions. The most restoration-minded choice is generally the one that preserves the truck’s proper size, construction type, and heavy-duty 16.5-inch wheel relationship.

Appearance should be balanced with fitment accuracy, especially on older trucks that may have seen wheel changes during their working lives. Buyers chasing strict originality should confirm historical details through truck-specific references, while most owners can make solid progress by matching the correct size first and then choosing the tread series that best suits the intended presentation.

Tire construction changes the overall character of a restored 1978 Ford F-350 because bias-ply and radial tires present the truck differently even when they share the same 16.5-inch wheel diameter. This model year includes both numeric bias-ply fitments and a radial 8.75R16.5 application, so construction is part of the visual decision as well as the fitment decision.

A bias-ply truck tire often supports a more traditional work-truck presentation, while a radial application may suit a truck already configured that way. The key is not to treat appearance as separate from fitment: wheel width, exact size, and the truck’s actual configuration should stay in focus so the restored look does not come at the cost of a mismatched setup.

Yes, modifications can affect tire fitment on a 1978 Ford F-350 even when the tire size itself looks correct on paper. Aftermarket wheels, altered wheel width, suspension changes, steering components, or body repairs can all change the way a 16.5-inch truck tire sits and clears the vehicle, especially on heavy-duty and dual-rear-wheel applications.

That matters because this truck already has several legitimate size paths depending on configuration. A modified F-350 should be checked for actual wheel dimensions, axle position, and clearance at full steering travel and suspension movement before new tires are mounted, rather than assuming an older replacement size still makes sense after years of mechanical changes.

Before driving a 1978 Ford F-350 on new tires, inspect the wheels, valve stems, lug hardware, and the general condition of the steering and suspension. The tires themselves should be checked for proper inflation, secure mounting, and any obvious contact issues, especially on trucks using heavy-duty 16.5-inch sizes or position-specific front and rear applications.

A short initial road check is a smart follow-up once everything is mounted. Pay attention to tracking, vibration, unusual rubbing, and air retention, then recheck inflation after the first drive. On an older F-350, that basic inspection routine is especially useful because long service life, stored periods, and prior repairs can expose problems only after the truck returns to the road.

Tires on a collector or low-use 1978 Ford F-350 should be maintained with regular pressure checks, visual inspections, and careful storage habits. Even when tread looks good, older truck tires deserve attention for sidewall cracking, bulges, cuts, flat spotting, and slow air loss. That applies to both bias-ply and radial fitments on this model year.

A truck that sits for long periods benefits from being stored away from prolonged sunlight, moisture, excess heat, and ozone-producing equipment. It also helps to inspect the tires before every meaningful drive rather than assuming low mileage equals good condition. On a heavy-duty pickup, tire age and condition can matter just as much as the size molded into the sidewall.