1978 International Tire Fitment Guide

1978 International vehicles in this guide use three tire sizes: 225/75R15, H78-15, and HR78-15. All three apply to the 1978 International Scout II, and all three mount on 15-inch wheels. Where product fitment details are available, 225/75R15 is paired with approved rim widths from 6.00 to 8.00 inches or 6 to 7.5 inches depending on the tire, while H78-15 uses 5.50 to 7.00-inch rims.

That means a Scout II owner usually starts by confirming the size code already on the truck or deciding what type of driving and appearance is most important. The wheel diameter remains consistent across the three choices, but the tire construction and approved wheel-width range can change, so it is wise to verify the actual wheel before settling on a replacement size.

H78-15 is an alphanumeric bias-ply size used on the 1978 International Scout II. The H identifies the tire's size class within the older alphanumeric system, and the 15 indicates that it fits a 15-inch wheel. In this application, H78-15 appears as a bias-ply construction rather than a radial, which affects both its appearance and the way it behaves on the road compared with later metric radials.

A Scout II owner considering H78-15 is usually looking for a more traditional late-1970s truck presentation, especially when paired with a wide whitewall or a workmanlike blackwall. Before using it as a substitute for a radial-marked size, confirm that the wheel width falls within the 5.50 to 7.00-inch range and that the handling character of a bias-ply tire suits how the truck will be driven.

225/75R15 is a modern metric radial size used on the 1978 International Scout II. The 225 is the nominal section width in millimeters, 75 is the aspect ratio, the R confirms radial construction, and 15 is the wheel diameter in inches. This size appears with both narrow and wide whitewall treatments and carries load ratings from 1,874 pounds at 35 psi to 2,094 pounds at 32 psi depending on the tire.

For many Scout II owners, 225/75R15 is the easiest size to understand because it follows the familiar modern radial format. It is still important to check the actual tire you are considering, since one version may call for a 6.00 to 8.00-inch wheel while another is approved for 6 to 7.5 inches, and that can influence which product makes the most sense on your truck.

The 1978 International Scout II can use H78-15 as a bias-ply tire or radial alternatives in 225/75R15 and HR78-15. H78-15 leans toward a more traditional period presentation and a more vintage driving feel, while the radial choices are better aligned with owners who want a more settled road manner for regular use. All three fit 15-inch wheels, so the key difference is usually construction rather than wheel diameter.

That choice should follow the purpose of the truck. A restoration aimed at a strong era-correct visual impression often points toward the bias-ply size, while a Scout II that sees frequent road miles often benefits from staying within one of the radial options. The smartest starting point is to decide whether originality of look or day-to-day drivability matters more to you, then confirm wheel width against the specific tire.

1978 International Scout II tires are available with several sidewall styles depending on size. The 225/75R15 radial appears in both wide whitewall and narrow whitewall form, while H78-15 bias-ply choices include wide whitewall and blackwall versions. That gives the Scout II owner a broad visual range, from more upscale whitewall styling to a more utilitarian truck look.

Sidewall style can change the character of the vehicle as much as the size code itself. Whitewalls tend to suit a restored or more polished presentation, while blackwalls better match a rugged, working-truck, or off-road-oriented appearance. If originality matters for a judged vehicle, compare your choice with factory literature, period photography, or a marque club standard before finalizing the look.

Three brands cover the 1978 International Scout II across the available sizes: BFGoodrich, Coker Classic, and American Classic for 225/75R15, plus Coker Classic and STA for H78-15. That means the metric radial size has the broadest brand spread, while the bias-ply alphanumeric size concentrates on more traditional vintage-style offerings. Each brand approaches the Scout II from a slightly different visual angle through sidewall treatment and series character.

Brand choice matters most after you have narrowed down the size and construction you want. If your priority is a whitewall radial in a modern metric format, 225/75R15 offers the most variety. If your goal is a classic bias-ply truck presentation, H78-15 focuses the search much more tightly and makes it easier to compare style details such as blackwall versus wide whitewall.

Rim-width requirements for 1978 International Scout II tires depend on the size and, in some cases, the specific product. The 225/75R15 radial uses approved wheel widths of either 6.00 to 8.00 inches or 6 to 7.5 inches depending on the tire. The H78-15 bias-ply size uses 5.50 to 7.00-inch rims. All of these options share a 15-inch wheel diameter, but they do not all share the same width window.

That makes wheel measurement an important part of selecting a tire, especially on a Scout II that may have had wheel changes over the years. A tire that physically mounts on a 15-inch wheel is not automatically ideal for every 15-inch wheel width. Confirm the actual width before choosing between the metric radial and alphanumeric options so the tire can operate within its intended shape and load range.

The three tire sizes used on the 1978 International Scout II all share a 15-inch rim diameter, so they are aligned at the wheel-diameter level. That means an original 15-inch Scout II wheel may be compatible with 225/75R15, H78-15, or HR78-15 from a diameter standpoint. Wheel width is the next checkpoint, because 225/75R15 and H78-15 do not use identical approved width ranges.

A truck still wearing its factory wheels may accept more than one of these sizes, but the correct answer depends on the actual wheel width and the tire you choose. Owners of restored or modified Scout IIs should measure rather than assume, since many trucks have seen wheel swaps over the years. Confirming width before mounting helps avoid choosing a tire that looks right on paper but is not ideal on the wheel.

A 1978 International Scout II should be stored clean, dry, and out of direct sunlight, with the tires kept away from ozone-producing equipment such as electric motors, welders, and air compressors. Maintain proper inflation during storage, and if the truck will sit for an extended period, move it occasionally or support it in a way that reduces prolonged loading on one contact patch. Bias-ply tires tend to flat-spot more readily during long static periods than radials.

That matters on a Scout II because many collector 4x4s are driven seasonally rather than weekly. Good storage habits help preserve sidewall appearance, reduce stress cracking, and make the first drive after a layup period more predictable. If your truck runs bias-ply H78-15s, storage discipline becomes even more important because they generally show the effects of long idle periods sooner than radial alternatives.

Tires on a 1978 International should be judged more by age and condition than by miles driven. A collector vehicle often accumulates very little mileage, so tread depth alone can be misleading. A practical rule is to evaluate them closely once they are in the five- to seven-year range and to treat about ten years as a serious replacement point regardless of remaining tread, with the DOT date code used to determine actual age.

That approach fits the way most Scout IIs are used today. Weekend use, trail events, and long storage periods can age a tire long before it appears worn out. Sidewall cracking, repeated loss of air pressure, vibration, or changes in ride quality are all reasons to inspect more closely, even if the tire still looks serviceable from a distance.

Tires on a 1978 International Scout II should be inspected before every drive and again before any longer outing. Look for cracking, bulges, irregular wear, embedded objects, and signs that inflation pressure is not holding steadily. On an older collector truck, it is also wise to examine valve stems and the condition of the spare, since age-related failures often appear there first.

Frequent inspection is especially important on a vehicle that may sit for days or weeks between uses. A quick walkaround catches many of the problems that can spoil a road trip or trail day before the truck even leaves the garage. If the tires have been in storage through a season change, pay extra attention to pressure and sidewall condition before resuming regular use.

A 1978 International Scout II belongs to an era when bias-ply and radial construction overlapped in the market, so both period-style alphanumeric sizing and more modern radial sizing are relevant when restoring one. In this fitment range, H78-15 represents the traditional bias-ply route, while HR78-15 and 225/75R15 represent radial directions on the same 15-inch wheel diameter. Original-equipment brand choice could vary by market, trim, and delivery details, so size and construction usually matter more than chasing a single brand assumption.

For a restoration, start with the size code shown on your truck's original paperwork, surviving tires, or factory labeling if present. If those references are gone, period brochures and Scout-focused clubs can help confirm what is most appropriate for your build. That extra check is worthwhile because a Scout II restored for historical accuracy may call for a different tire presentation than one restored for road touring.

Correct tire fitment absolutely matters when showing a 1978 International Scout II, especially in classes that value authenticity. Judges and knowledgeable enthusiasts often notice whether the truck is wearing the right size family, the right construction type for the restoration theme, and a sidewall style that suits the era. A radial tire on a truck being judged as strictly original, or a sidewall treatment that looks out of character, can weaken an otherwise careful presentation.

That does not mean every Scout II must wear the same tire to be respected. It means the tire should support the story the truck is telling, whether that is factory-stock, dealer-era custom, or period trail rig. If the event has formal standards, check them ahead of time and compare your choice against marque-club guidance so the tire complements the restoration instead of distracting from it.

The 1978 International Scout II has both whitewall and blackwall options depending on size. In 225/75R15, the radial choices come with wide whitewall and narrow whitewall treatments, while H78-15 includes both wide whitewall and blackwall versions. The visual difference is significant: whitewalls give the truck a more finished and era-styled presentation, while blackwalls create a plainer, more functional look.

Choosing between them depends on what kind of Scout II you are restoring. A polished, street-oriented truck can wear whitewalls convincingly, especially if the rest of the build leans toward a well-optioned late-1970s appearance. A more rugged or utility-minded Scout often looks more natural on blackwalls. Period photos, sales literature, and club references are the best tie-breakers when authenticity is the priority.

1978 International Scout II tires can be appropriate for highway use when they are in good condition, correctly inflated, and matched to the way the truck is driven. Radial choices such as 225/75R15 and HR78-15 generally align better with steady road use than a traditional bias-ply design, while H78-15 is more rooted in vintage construction character. Tire condition matters at least as much as tire type on a vehicle of this age.

The broader safety picture on a Scout II also includes the truck itself. Brakes, steering, suspension wear, alignment, and overall mechanical health can limit comfortable highway use long before a reproduction tire reaches its own design threshold. Treat the tires as one part of the system, and make sure the whole vehicle is ready for sustained speed before planning a longer highway run.

Inflation pressure on a 1978 International Scout II should follow the vehicle manufacturer's recommendation for the application and the tire manufacturer's pressure limits for the specific tire. Among the available options, 225/75R15 tires carry load and pressure pairings of 1,874 pounds at 35 psi or 2,094 pounds at 32 psi depending on the tire, while H78-15 appears at 1,770 pounds at 32 psi or 1,830 pounds at 45 psi depending on the tire.

Those numbers are load-capacity references, not a one-size-fits-all instruction to inflate every Scout II tire the same way. The safest approach is to begin with the vehicle's recommended pressure for the size and use, then confirm that the tire itself is being operated within its rated limits. Pressure should be checked cold and adjusted consistently, especially before highway driving or carrying extra cargo.

Before taking a 1978 International Scout II on a longer drive, inspect all four tires and the spare for cracking, cuts, bulges, uneven wear, and proper cold inflation. Make sure the valve stems are sound and that the tires have not lost pressure during storage. A longer drive is also a good time to verify that the tread area is free of punctures or damage that may not be obvious in routine around-town use.

That tire check should be part of a broader pre-trip inspection on a vintage 4x4. Wheel-bearing condition, brakes, steering play, fluid levels, lights, and charging system health all matter on a Scout II that may have spent more time parked than driven. Starting with the tires gives you the quickest picture of whether the truck is physically ready to leave the garage and settle into a full day on the road.