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by Huw Evans  More from Author

Find and fit the right rims and rubber for your classic Corvette.

Photos by Huw Evans, Legendary Motorcar, and GM.


There’s no question that wheels and tires completely alter the look of a car. And it doesn’t matter if it’s a $500 jalopy or a $500,000 exotic: get the right wheels and tires and the car looks dynamite, get it wrong…and perhaps you best leave the ride parked at home.

Wheel and tire shopping is probably one of the hardest elements when it comes to your vehicle, and those machines that look just right are often the result of their owners spending many hours researching and test-fitting different wheel and tire combinations. When it comes to Corvettes, things are perhaps even more crucial. It doesn’t matter whether you’re using stock wheels or aftermarket units, there are some designs (not to mention tire sizes) that fit certain model years better than others. With that in mind, we at Corvette & Chevy decided to do a bit of investigating. We picked four generations of Corvettes, examined their factory wheel and tire sizes, and discovered what fits and what doesn’t when it comes to bigger rims and rubber.


C1 1953-62

As far as the solid-axle cars go, one thing you’ve got in your favor is consistency. From 1953 to 1962 there were few changes to the wheels, tires, or chassis. These cars boast a front track width of 57 inches and a rear one of 59 inches. Five-lug wheels were standard through the production run. On the very early 1953 cars, stock tires were 6.75x15 US Royal bias-plies, mounted on 15x5-inch pressed steel wheels. Later during the model year, Firestone tires in the same size were made available. For 1954, tubeless tires were adopted, and some cars were also fitted with BFGoodrich rubber for the first time. The wheel cover design was changed for 1956 and this required small nubs on the wheels to secure the new covers, which were larger in diameter. The cover design was changed again slightly for 1958, though the wheels themselves remained the same. This design would endure through 1962. However, during that final year of production, the wide whitewall tires were substituted for narrow bands and special 15x5.5-inch wheels were available as a no-charge option. Since most owners tend to keep them stock or restore them to original condition, there isn’t much of a problem regarding wheel and tire fitment. Companies like Coker Tire and Zip Products provide reproduction, original-style tires and wheels. If you’re looking to use modern radials that provide a period look, yet offer far greater improvement in handling, this is also an option. The most suitable sizes for 1956-62 Corvettes are 205/75/15s through 225/70/15s, which are available from American Classic, BFGoodrich, and Goodyear, among others.

For more radical options (read wider tires), the choices for C1s become more restrictive. The biggest problem is rear fender clearance. Even with stock-sized tires, the location of the rear leaf springs, trunk floor, and especially frame rails means you have less than six inches of clearance between the sidewall of the tire and the frame/inner wheelwell. Thus in order to mount wider tires, you’ll need wheels with a unique offset to provide adequate clearance–yet you’ll also want a wheel and tire combination that doesn’t stick out of the rear fender openings, which can spoil the overall look of the car. In most cases, a set of 15x7-inch aftermarket mags or aluminum wheels are the best choice, on a 60- or 55-series tire that’s between 205 and 235 mm wide. Also, remember that very wide front tires can cause tramming especially on badly rutted roads, putting additional stress on the car’s steering components. It’s something to think about, especially if the car is going to be used primarily for street driving. Upgrading to a complete, modern rack and pinion system like that offered by Jim Meyer Racing Products (which is specifically designed for these cars) can help, but again think about your objectives, how important originality is, and how much you want to spend. At the back, using a tire that’s wider than 255 mm will require modifications to the frame rails and also the trunk area, possibly even mini tubs. Again this is something you’ll need to consider. If the car is in reasonable shape (as many existing C1s are) and unless you have a sizeable budget, try and stick with a 15x7-inch wheel and a maximum 225-section tire. This will still provide a good blend of modern performance and grip, and mounted on a classic 15-inch American Racing Torq-Thrust, Cragar S/S, or similar will lend a period look that’s well suited to the styling of these cars.


C2 1963-67

There’s no question that the Sting Rays rank as the most prized Corvettes ever built. At the time of their introduction, these cars represented a huge leap forward in style and performance, particularly where handling was concerned. The Sting Ray received an entirely new chassis and suspension (a new independent design was adopted for the rear), which resulted in a narrower track (56.8 inches front, 57.6 inches rear). Stock tire size remained 6.70x15, though two different kinds of wheel were available. The first was a 15x6-inch steel wheel that featured a full wheel cover with a new design, and the second was an optional 15x6-inch knock-off cast aluminum wheel. These featured attractive finned spokes, and were mounted on the car via a central adapter, cone, spinner, and center cap (see sidebar for the correct installation procedure). For 1964, the full wheel cover design was changed and this continued into 1965, by which time 15x5.5-inch pressed steel wheels continued as standard (the knock-off aluminum wheels continued as an option). The standard hubcap design was revised once again for 1966, though wheel size was unchanged. The knock-off wheels also got a darker gray finish this model year.

For the Sting Ray’s final season, the knock-offs were replaced by bolt-ons; they featured a similar design, but with a traditional five-bolt mounting hub beneath a revised, removable center cap. In addition, 1967 also saw the debut of the Corvette Rally wheel; a pressed-steel 15x6-inch design with large slots to help brake cooling. Special center caps were fitted to 1967 cars that received these wheels, along with bright trim rings.

The original Sting Ray wheels are available today as reproductions. And for those who find the original knock-off simply too expensive and fiddly, Zip Products offers a bolt-on reproduction that looks like the original, with a spinner and center cap that covers a regular wheel hub at a fraction of the price.

In terms of tires, the 1963-67 Corvettes came with US Royals, BFGoodrich Silvertowns, Firestones, or Goodyears depending on availability. These tires often came with a 1-inch white sidewall band (7/8 or 5/8-inch in 1965), and reproductions are available today. For 1965, tire size was increased to 7.75x15 and for the first time, the hallowed Firestone Super Sport Goldline became available as a factory option. These tires continued for 1966 and today, accurate reproductions are available directly from Firestone, made from modern materials but created using the original factory blueprints.

For 1967, Firestone’s infamous Redline made its first appearance on the Corvette, superceding the Goldline. These were sized at 7.75x15 inches and, like the Goldlines, have been reproduced by Firestone and are available today. Besides Firestone, BFGoodrich and Goodyear also came out with their own Goldline, and later, Redline tires. Goodyear’s Power Cushion redline was specifically designed for the 1967 Corvette and today these are among the most desirable reproduction tires available, not to mention a requisite for a Top Flight restoration.

A growing trend among Sting Ray owners is to fit radial tires that look like the old bias-ply white, Goldline, and Redline tires, but provide far greater levels of grip and an improved ride. In keeping with the period look and stance, the most popular sizes are 205/75R15, available from Coker Tire and several specialist vendors.

If you’re looking at installing bigger aftermarket wheels and tires, then you’ve got some homework to do. Bear in mind that like most cars of the period, 1963-67 Corvettes weren’t designed to accommodate excessively large wheels, so as a general rule of thumb it’s best to stick with 16-inch rims, though it is possible to go as big as 17x8s. A very good place to start when shopping for aftermarket non-stock sized wheels is Wheel Vintiques (www.wheelvintiques.com), which offers a huge variety of wheels designed for classic cars in standard and custom sizes. As for tires, if you go with a 16- or 17-inch wheel you’ll need a lower sidewall height, preferably 45-60 mm to provide adequate fender clearance. Remember: the shorter the sidewall, the firmer the ride. Tire width is also something you’ll need to take into consideration. Your best option is to check with a tire specialist once you’ve selected the wheels you want to use (some are listed at the end of this article).


C3 1968-82

On the outside, the controversial 1968 model looked radically different, but under the skin it was pretty much a carryover, though the front and rear track was widened slightly to 58.7 inches front, 59.4 inches rear, and the fender openings were larger. By 1968, tire technology was starting to advance quite rapidly, and standard equipment were F-70 15 bias-plies, mounted on either 15x7-inch steel Rally wheels (with a different center cap and trim ring design to those from 1967), or pressed steel 15x7-inch wheels with full finned wheel covers. For 1969, GM fitted 15x8-inch Rally wheels which, other than being one inch wider, looked identical to those fitted for 1968. These would remain standard fitment on third-generation Corvettes sold through 1977. For 1973, GM introduced a new, 15x8-inch, 8-spoke, slotted aluminum wheel designed to go with new radial-ply tires. However, these wheels were found to have structural problems and many sets were recalled, making surviving 1973 Corvette alloys very rare. A modified design, introduced for the 1976 models, was much stronger and more durable. It lasted through the end of production in 1982. It’s interesting to note that the 1978 Corvette Indianapolis Pace Car replicas featured a special version of this wheel with a polished aluminum (instead of black) center section, and a red stripe on the rim lip. These wheels (sans the red stripe) were standard fitment on 1980-82 Corvettes. The 1982 Collector Edition, featured finned, cast aluminum 15x8-inch wheels with a removable center cap that hid the lug nuts (not unlike the bolt-on 1967 rims).

As for tires, third-generation cars required wider rubber to compensate for suspension changes and the car’s wider track and wheels. Goodyear engineers worked with General Motors and created the F70 15 Speedway, a wide-tread tire designed for optimum performance at the time. These tires were available with raised white letter, white line, or red line sidewalls. Today reproductions are available from Goodyear or through specialist Corvette vendors like Zip Products. These tires are the perfect complement to your early C3 factory restoration.

Starting in 1973, GR 70-15 steel belted radial-ply tires were offered as a factory option. However during initial testing, they proved to deliver performance inferior to that of the old bias-plies, though by 1975 they were standard fitment. Goodyear Steelgard and Firestone 500s were the primary OE choices during these years, though they gave way to Firestone S/S radials and Goodyear’s GT Radial by the end of the decade. The very last C3s came with Goodyear Eagle GTs, sized at P255/70R15, which were among the best-performing tires in their day (the 1982 Collector Edition cars featured lower-profile 60 series tires).

In terms of bigger wheel and tire choices, you’ve got more options with C3s than the earlier cars. Replacement Rally wheels and even the later GM alloys are widely available via aftermarket vendors. Thanks to the larger fender openings, bigger 16- and 17-inch wheels fit with ease on these cars and it’s possible to go as large as 18s, without any fender clearance issues. Because wheel choice is all about personal preference, take your time, try several different vendors that offer larger wheels designed to fit C3 Corvettes, and ask plenty of questions. The same goes for tires: you can go bigger than with the earlier cars. A modern 245/45/R17 will fit with no clearance issues, and you can go as big as a 255/40/R18 in the front and a 275/35R18 in the rear. Beyond that, any larger tires or wheels will likely require custom backspacing and possible fender and frame modifications. Furthermore, 19-inch or bigger wheels simply aren’t that practical on cars like this, and don’t complement the C3’s proportions very well.


C4 1984-87

Because our story largely focuses on the earlier Corvettes, we’ll only give a brief mention regarding C4s, specifically the earlier cars. And there’s a reason for this: The 1984-87 Corvettes came with a very unique design–a 16x8.5-inch cast aluminum wheel that features an unusual 36 mm offset. A 16x9.5-inch version was offered from 1985 onwards with a 38 mm offset as part of that year’s Z51 handling package, though depending on when a C4 was built, it could have been originally equipped with either. The only way to tell is by removing the wheels and inspecting them. The original equipment aluminum wheels on 1984-85 Corvettes feature a black center section, on the 1986 models it’s the same color as the rest of the rim, whilst on the 1987s the center section is gray.

One thing that was consistent throughout the production run was tire sizes. P255/60R16 Goodyear Eagle NCTs were the original equipment tire on 1984 Corvettes, changed to Eagle GTs for 1985, though size remained the same. These tires were known as Gatorbacks, due to the unidirectional tread that resembled the scales on an alligator’s back. This special tread design featured unique sipes, designed to remove water as quickly as possible when driving on wet surfaces, thus improving grip. It was a concept derived from Goodyear’s then-current Eagle Formula 1 rain tire. However, the tread design meant that these tires could only be changed from front to back and not side to side. The Gatorbacks were the precursor to all modern high-performance tires.

In terms of replacement wheels and tires, the 1984-87 Corvettes are rather unique, in that wheels designed for 1988 and later cars won’t fit, since the larger 17-inch wheels originally fitted to these cars featured a greater 56 mm offset. One exception is the 1990 Corvette ZR-1 wheel, which features the same 38 mm offset as those on the 1985-87 Z51-equipped cars. The ZR-1 rear wheels were a massive 17x11 inches in size, and the car required special flared-out rear bodywork as a result. These make a great choice for a 1984-87 modified Corvette, and these days can often be considerably cheaper than forking out for a set of massive aftermarket rims. Considering that most current aftermarket C4 wheels are designed for the 1988-96 cars, you’ll need wheel adapters to install them on a 1987 or earlier fourth-generation Corvette. In terms of actual wheel size, you can go as large as 17 or 18x9 on the front, and up to a massive 17 or 18x11 out back. As for tire sizes, the biggest you can fit without causing issues are 275/40R17 or 275/35R18 at the front, and a monster 315/35/R17 or 305/35R18 on the rear. Good hunting.





During the course of their production run, first-generation Corvettes retained the same-size wheels, though the design was modified on 1956 models like this to accommodate a new, slightly bigger wheel cover.




Tires on early Vettes were 6.70x15 bias-plies, from US Royal, Firestone (shown), or BFGoodrich. For the restorer, reproduction tires, created using the original factory drawings, are available today.




As you can see, there isn’t a huge amount of wheel/tire clearance on an early solid axle Corvette, even with original-sized tires, due to the location of the framerail and leaf spring in relation to the wheel hub. As a result, if you’re thinking of installing larger rubber, you need to be careful in your selection of a wheel and tire combination.




Although it may seem somewhat laughable now, in its day, a 1956 Corvette equipped with 6.70x15 Firestones like this was a serious handler.




For the 1963 Sting Ray tire size was unchanged, though a new design of wheel cover was specified. These particular wheel covers are unique to this model year.




Tire sizes on early second-generation cars mirrored those of the C1s, the factory size being 6.70x15. This lasted through the end of 1964 model year production.




Besides steel wheels with full wheel covers, a set of handsome knock-off aluminum wheels were available beginning in 1963. For the 1965 model year, tire size was enlarged to 7.75x15, though wheel dimensions remained unchanged.




For the Sting Ray’s final year, the full wheel covers and knock-offs were replaced. One design that superseded them was this handsome 15x6-inch Rally wheel, with chrome trim ring and center cap.




To go with the new wheel, Goodyear designed a tire specifically for the Sting Ray, the Power Cushion. Today, reproductions of these tires are highly sought after for NCRS Top Flight restorations. 1967 was also the first year for Redline tires.




Besides the Rally, 1967 also saw the debut of bolt-on aluminum wheels. These looked similar to the knock-offs, but featured a traditional five-stud hub integrated with the rim, beneath a center cap.




With the center cap removed you can see the hub of this bolt-on 1967 wheel. Like all Corvettes, 1967 models use five-lug wheels.




Here you can see the backside of the same wheel, off the car. Note that this Sting Ray has been fitted with modern 205/75R15 radial tires, as the owner likes to drive the car at every opportunity.




Third-generation Corvettes looked radically different to their predecessors, but were mechanically much the same. A wider track and larger standard tires were fitted. This is a 1972 Stingray with 15x8 inch Rally wheels and F70 15 Firestone Wide Oval bias-plies, one of the two major OE tire choices on these cars in the early years–the other being Goodyear.



Due to their widespread popularity, the 15x8-inch Rally wheels, as originally fitted to 1969-76 Corvettes, are fairly cheap and easy to come across. Shown are some good examples that were picked up at a swap meet. The Goodyear Eagle GT II tires date from the mid-1980s.




Chevrolet tried to use new aluminum wheels on the 1973 Corvettes, but soon dropped them because of structural problems. By 1977, an improved design had been introduced and this would last all the way through the end of C3 production in 1982. By the mid-1970s, radials were standard on the Corvette, including Firestone 500s as shown in this factory photograph.




Thanks to larger fender openings, you can install much larger wheel and tire combinations on C3 Corvettes than on the earlier cars. This 1979 sports 17x8-inch American Racing Torq-Thrust IIs and Fuzion 255/50R17 tires up front with no clearance issues.




When it comes to C4 Corvette wheels and tires, there’s a sizeable difference between the early 1984-87 cars and the later 1988-96 models. Pictured is a 1986 roadster with the original equipment 16x7.5-inch wheels and Goodyear Eagle P255/60R16 Gatorbacks.




The main concern with early C4s concerns the factory wheel offset, which can be from 36 to 38 mm. As a result, because many aftermarket wheels for these cars are designed for the 56 mm offset from 1988 onward, you’ll need adapters to fit them on the 1984-87 cars.




An increasingly popular option for owners of C4s is to retrofit C5 wheels to their cars, but again, you’ll need to measure the offset and backspacing in order to mount them correctly on the older car.


Special thanks go out to Adrian Chadwick and Legendary Motorcar Company (www.legendarymotorcar.com) for their assistance with this article.


INSTALLING KNOCK-OFF WHEELS



Despite what the name suggests, installing genuine knock-off wheels on your Sting Ray isn’t an easy task by any stretch. Before you begin, you’ll need to note that the spinners and wheel adapters for the left and right sides of the car are not interchangeable. You can tell left side spinners by the way the wings point counter-clockwise; for the right side ones, they point clockwise.

Before you install your wheels, you’ll also need to make sure that the drum or rotor hubs are free from dirt and grime, and that they sit completely flush with adapters for the knock-off wheels. You should also check fitment by placing the threaded end of the adapter in the center of each wheel.

1. Install the correct side adapters by aligning the holes with the studs on the Corvette’s brake drum or disc. It’s recommended to use longer thread length lug nuts than the OE pieces for a more secure fit. Once the nuts are installed, torque them to approximately 80-85 lb-ft.

2. With the adapters mounted, place the knock-off wheels onto them and make sure the holes on the back of the wheel align with the stud pins on the adapter. If they don’t sit flush, then there’s a problem with the wheel or the adapter.

3. Next, place the cone over the top of the adapter. Knock-off cones were prone to rattling, so to cure this problem, place some silicone around the inside of the cone.

4. Once the cone is installed, you can attach the spinners. Carefully turn the spinner toward the rear of the car. You’ll need an assistant to step on the brake pedal to prevent the wheel from moving, and also a lead hammer to hit the spinner wings, which will help tighten it (lead is a soft metal and won’t damage the spinner). You’ll know when the spinner is fully tightened, because a groove on it and the adapter will line up against each other. With that, the task is completed.


WHEEL TERMS

Offset: Measurement of the hub surface area in offset from the centerline relating to the width of the wheel.

Backspacing: Measurement from the hub surface contact area to the outside of the inner wheel rim.

Front Spacing: Measurement from the hub surface contact area to the outside of the outer wheel rim.

Center Bore: Location hole machined into the center of the wheel. Each wheel is designed to have a certain sized center bore to mate with a specific vehicle.

Pitch Circle Diameter: Measured diameter of the center circumference of the centerline of lug nut holes, for Corvettes there are five holes.


SOURCES

Coker Tire
800-251-6336
www.cokertire.com

Corvette America
800-458-3475
www.corvetteamerica.com

Discount Tire
800-589-6789
www.discounttire.com

National Corvette Restorer’s Society
513-385-8526
www.ncrs.org

The Tire Rack
888-541-1777
www.tirerack.com

Wheel Vintiques
559-251-6957
www.wheelvintiques.com

Zip Products
800-962-9632
www.zip-corvette.com

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