Reprint Courtesy of Source Interlink Media Archives
To appreciate the ’65 GTO’s story and its impact on the era’s market and car culture, we dug up this article that ran in Car Craft’s March ’65 issue. It features a road test conducted by The Chaparels Car Club of Tustin, California, and coordinated by the legendary LeRoi “Tex” Smith. (After more than 50 years in the magazine business, Tex Smith is still at it, offering up his inimitable style as a columnist for hotrodonline.com.) We hope you enjoy this time warp back to when the GTO was still a hot new car on the scene. —Don Keefe
Conducted by the Chaparels Car Club, Tustin, California
Coordinated by Leroi Smith, ICCA Field Director
(Editor’s note: LeRoi “Tex” Smith, field director of the International Car Club Association and official club coordinator of Car Craft’s new car club road test series, has had a long association with special automobiles. Included in this experience is extensive sports car racing in Europe, thus it is that we wanted to include at the outset of the GTO test story a few of his enthusiastic remarks after driving the car.)
“Frankly, I’ve never been so thoroughly impressed by an American car. I’m a firm believer that the U.S. produces the best automobiles in the world, and that virtually any factory could, upon necessity, build a special car to compete successfully with the best of any European racing builder. In this particular GTO, there is everything the most critical purist would demand—exceptional flexibility of engine, transmission, and rear end; and a superior chassis/brakes combination. It’s the most complete dual-purpose American car I’ve ever seen, perfect for high-speed cruising or limited GT racing (ideal for hill climbs), and absolutely charming for around-town hops.”
The new Pontiac perimeter frame is responsible for the extra total strength factor of the
When Car Craft asked us if we wanted to test the GTO, it didn’t take a special club meeting to finalize an answer. Man, we were all for it. In fact, we felt this was something of a privilege, since the Paragons of nearby La Crescenta had done last month’s Dodge Coronet series. Seldom will two clubs in one state be picked, so we naturally leaped at the chance.
As delivered, our test Pontiac GTO had 1600 miles on the odometer, mostly due to use in some special Hollywood-produced Pontiac commercials. The engine was broken in, the brakes were well seated, and the gears loosened up just right.
Car Craft told us the car was one of the special jobs, with heavy-duty suspension, metallic brakes, four-speed transmission, and the new high manifold 389 V-8. A couple of the fellows in the club own Pontiacs, so we felt we’d at least be on first base in the acquaintance department. But before we get into our actual driving results and reactions to the car, let’s jot down the basic technicalities of the vehicle.
Part of the recent popularity of the new GTO must certainly be attributed to the frame, which gives excellent rigidity under the most trying conditions. Called a swept-hip-perimeter design by the factory, the framework is basically a rectangular box configuration with three cross members.
The side rails are located just inboard of the body rocker panels, and extend from the cowl rearward to the fender-well area. On the closed-top vehicles, the side-rail section looks like a “C” with a slightly downward-bent top. The convertible has a reversed C-section added to the inside of the channel for added strength.
The swept-hip term comes from the shape of the frame at front and rear ends, where it sweeps inward and upward before continuing. From the cowl area forward, the framework is completely boxed, constructed with an integral deep-dip front crossmember. The upper A-arm and coilspring perches are located on the frame at either end of this strong crossmember. The frame extensions running forward for radiator and sheetmetal support are also boxed. This latter item is quite important, as it provides very stiff mounting for the short bumper brackets, giving a strong bumper. When you jack up the front of this car with a bumper jack, everything moves, not just the bumper.
At the rear, the inward/upward sweep starts about the rear seat and is also boxed completely. At the innermost apex of the sweep are two rearend locating-arm mounts. The rear crossmember is nearly straight, with coilspring-mounting flanges directly adjacent. From the top of the kickup rearward, a single channel extends straight back to a terminal-channel crossmember, which is both a bumper-mounting area and rear body support.
A fourth crossmember becomes a part of the structure when the transmission is added. This member mounts via rubber bushings to either side rail. The bushings cut down on the amount of engine vibrations transmitted into the car body. On the subject of passenger-compartment noise reduction, soft butyl-rubber mounts are used at all body bolt points (there are seven on each side, which also contributes considerably to the rigidity of the completed car).
Here’s where we came unglued—not at the standard package so much as with the options offered. Of course, you’ve got to start with something awfully good. Springing is by coils all around, designated as Heavy-Duty items on all GTOs, with wheel rates of 89 and ll0 pounds per inch, front and rear. These springs are more than sufficient for any use, so very few would consider any other rates necessary.
The independent front suspension uses two spherical ball joints at top and bottom of the steering knuckle with “fixed-boot” grease seals. Under normal conditions, you can expect 12,000 miles or one year between grease jobs, if you use the specially recommended factory grease. The unequal length A-arms are made of heavy-gauge stamped-steel and pivot on the inner points through rubber bushings. The wide stance inner mounts of the A-arms assure a minimum amount of front-end alignment trouble, since such mounting tends to resist normal driving abuse.
Part of the GTO’s handling qualities come from the big stabilizer bar used up front. Standard at 0.938-inch-diameter, this bar bolts below the frame horn extensions in large rubber bushings and connects to the lower control arm well to the outer end for maximum travel. With this big bar, front end roll is reduced considerably, but normal up and down movement of the front suspension doesn’t seem too severely hampered.
The shocks normally fitted are valved for a firm ride, with even firmer options available. Our test car was fitted with the super-boss stiff thingies, which we really liked. But for average Joe Driver, the normal shocks will prove quite satisfactory. The rear suspension has coilsprings and a four-link locater.
One of the first things we noticed about this car was the lack of rear end movement (twist and hop), so we crawled under to look. It has two stamped U-section locaters that run forward from the bottom outer ends of the axle housings to the frame. These locaters run parallel with the frame. Castings integral with the third member housing (on top) provide mounting points for two more U-section locaters that also run forward. These two locaters are shorter than the bottom two, and bolt to the back of the rear crossmember. They intersect the framerails at about 45 degrees. Rubber bushings are used at all mounting points to reduce noise transmission.
With this locater system, axle wrap-up and sidesway is virtually eliminated. About all that’s left to the performance enthusiast is the addition of Air-Lifts to the coilsprings.
GTO rearends list the Safe-T-Track limited-slip differential as a low-cost option. One of
As with most American cars, the GTO offers two basic steering systems, power and manual. The rotary-valve safety power steering gear gives an assist only when required, and has been improved over previous models through the rotary valve feature. A “torsion bar” incorporated in the design gives a better “feel” and minimizes over-steering. The power steering ratio is 17 to 1. The standard manual steering has a ratio of 24 to 1, with the same basic recirculating ball-bearing design as the power unit. An optional quick steering manual unit is available upon request, with a ratio of 20 to 1.
Pontiac has made a definite effort to improve upon the efficiency of its brakes, which is a refreshing attitude from Detroit. Dictates of styling and cost have too long kept sufficient braking from the average American car, contributing to much of the scorn by sports car addicts. But the GTO offers braking for the most critical.
Of the standard hydraulic, internal expanding, two-shoe design, the 1965 items have finned drums with a 9-1/2-inch diameter. Giving a total swept area of 269.8 square inches, the standard brakes have linings with thicker secondaries and longer primaries.
Wider and heavier, the drums are offered in both iron and aluminum. In iron, the front drums are centrifugally cast in a corrugated steel shell while the rears are statically cast with 40 axial ribs around the outside. Both front and rear iron drums have cooling flanges that extend out into the airstream for better cooling. Aluminum drums are available as a front end option only, and metallic linings are available with all axle ratios except 3.08:1. These linings are standard equipment on all production line vehicles having a 3.90 axle ratio.
Our test car was equipped with the metallic linings and the power assist mechanism (Delco Moraine Power Brake). The power brake is a sealed, self-contained unit that fits on the firewall between the hanging type pedal and master cylinder. Engine vacuum is used to provide the pedal pressure assistance. The power brakes are suggested with the metallic linings, since the metallic brakes require much higher pedal pressures.
The GTO uses a modified (control arms instead of leaf springs) Hotchkiss rearend with a hypoid ring gear and pinion. Component parts have been beefed-up since ’63, and should give no trouble even under severe competition at the dragstrip, assuming normal maintenance, of course. The differential case is a one-piece unit with a cover plate at the rear. Steel axle housing tubes are pressed and welded into the cast case. The semi-floating rear axles are big enough for very rough usage and are supported at the outer ends by pressed-on heavy duty ball bearings. The pinion shaft is also big and is located by two tapered roller bearings.
There are seven different axle ratios available for various model cars. Identification of a ratio is from a code stamped on the rear of the righthand axle tube adjacent to the carrier or on the left rear brake drum surface. There will be two letters in this code identification, the first identifying the type of rearend (W-Standard, Y-Safe-T-Track, X-Standard with metallic brakes and Z-Safe-T-Track with metallic brakes) and the second denoting ratio. There are nine axle ratios listed, but only eight of them generally appear in print. They are B-2.56, D-2.93, E-3.08, F -3.23, G-3.36, H-3.55, K-3.90, and L-4.33. The ninth is a 4.11 to 1 ratio, normally listed as an optional option, along with the 4.33.
Pontiac calls its limited-slip differential the Safe-T-Track, and lists it as optional on all ’65 Tempests, regardless of axle ratio. A tag attached to one of the third member cover plate bolts identifies such an option. Very similar to the standard differential, the Safe-T-Track has an additional set of cone clutches and pre-load springs. In use, this assembly transmits power to the wheel having most traction, unlike a standard differential, which does just the reverse.
The Safe-T-Track is an extremely free-running unit, with no apparent binding on tight corners or deceleration. When the 335-horsepower engine is ordered, the standard axle ratio will be 3.23. With the 360hp engine, the ratio will be 3.55. This holds true for both the three- and four-speed manual and automatic transmissions.
A three-speed synchromesh transmission is listed as standard equipment in all Tempests. A cast iron case is used for the three-speed, enclosing helical gears made from drop-forged steel blanks, heat-treated and shotpeened.
The GTO offers the Hurst floor shifter as standard appointment, and two ratios can be purchased in the three-speed configuration. The first is 2.58:1, 1.48:1, and direct. The second is 2.42:1, 1.61:1 and direct.
Probably of most interest to any automotive buff is the four-speed alloy-cased gearbox. This is available as an option only and consists of two cases, the front holding the four forward gears and the rear case housing the Reverse gear. A fully synchronized design, the four-speed comes with a Hurst floor shifter and two different ratios. The wide-ratio box has 2.56:1, 1.91:1, 1.48:1 and direct, while the close-ratio transmission (available only with the 3.90 rear axle ratio) has 2.20:1, 1.64:1, 1.28:1 and direct.
For general driving in city traffic with only an occasional fling at the drags, the wide-ratio gearbox would probably be most satisfactory. This would allow more flexibility in any particular gear. The close-ratio box is for any condition requiring constant engine rpm, such as drag racing, hill climbs, slaloms, etc.
The floor-mounted Hurst shifter is located right at the edge of the bucket seat, and features an extremely short throw from First to Second, a slight spring-loaded jump to the right, and a slightly longer throw between Third and Fourth. Reverse is spring-loaded all the way to the left and forward. This short-throw shifter can be a bit tricky at first, but quite comfortable with experience. For a sports car type of bash, it’s ideal. A two-speed torque converter automatic is available, with a max torque multiplication off the line of 3.87 to 1. The governor is set for automatic upshift at 5,200 rpm.
The GTO is equipped with two basic ohv’s, both displacing a cool 389 cubic inches. The only difference between the two is a little matter of 25 advertised horsepower, derived at through camshaft timing and carburetion.
Jerry Jardine installed a set of his popular three-port headers on the car before last par
The 389 engine is a short stroke, 90-degree V design, with a reasonably thin-walled alloy cast-iron block. The bore is 4-1/16 inches, while the crank strokes a neat 3-3/4 inches. The flat-top aluminum pistons have a compression ratio of 10.75:1 and are fly-cut in the crowns for valve clearance.
The block has five main bearing supports, providing a very strong bottom end for the cast pearlitic malleable-iron crankshaft. The crank is fitted with heavy-duty Moraine-400 aluminum-on-steel main and rod bearings. Journal diameters are 3-inch, which means that a good amount of modifications can be made to the engine without undue worry about the bottom end falling out.
The heads are identical side for side, and are designed to flow water completely around the valve seats for better cooling. The valveguides are integrally cast in the head and consume the major length of the valve stem, cutting down on excessive valve sideplay. All ports are large in stock form, indicating a minor bit of shaping and clean-up only.
The valves are big, with intakes measuring 1.92-inch and exhausts of 1.66-inch. The intakes have a 30-degree seat angle; the exhausts use a 45-degree seat for better heat dissipation. Lift is set at 0.395 to 0.417-inch, which is quite reasonable for a hot street machine. The cast-iron camshaft has lobes ground at an angle to cause the lifters to rotate and is supported by five bearings. Special high-performance hydraulic valve lifters are included. The 335 engine has a valve timing of 273 intake, 289 exhaust (duration in degrees), 54 degrees overlap. The 360 engine features an intake of 288 and exhaust of 302, with an overlap of 63 degrees. The dual exhaust with low restriction mufflers and resonators is stock.
The 335hp engine is fitted with a single four-barrel carburetor. The bigger 360 engine has three two-throats with a mechanical progressive linkage. The throttle bore area of the single quad is 7.62 square inches compared to 12.19 for the triples. Under the conditions we’ve just listed, the 335 produces 431 lb/ft of torque at 3,200 while the 360 register 424 at 3,600. Under almost any set of rules, the 389 GTO engine must be rated as very good in showroom trim, and superb with a little “hot rod english.”
A transistor ignition is available, as is a seven-blade declutching fan. Chrome valve covers and carb cleaner sheetmetal adds to appearance, if not performance. To take care of any unusual heating problems, heavy-duty radiators are listed as options.
The bodies are of standard sheet steel, with no optional aluminum or fiberglass parts available for racing purposes. As it is, the car can be ordered without underseal or other sound-deadening material, which cuts about 130 pounds in total weight; further refining in the diet department should trim another 80 pounds easily. According to the printed material, the hardtop with small engine weighs 3,462 pounds and the coupe weighs 3,443. The big engine adds 16 pounds to this total, due to the heavier manifold and two extra carbs. Another 10 pounds is added by the automatic trans. As tested, our car weighed 3,660 on the strip scales, 1,995 pounds of this on the front end.
The GTO is distinguished by a pinstripe along the side, following the general upper outline of the fender line. The wheelbase of all models is exactly 115 inches, and overall length is 206.1 inches. Tread is 58 inches in keeping with the wide-track theme, both front and rear. Overall width is 73.4 inches; height for the closed body is 53.5 inches. Height at the cowl is 37 inches and ground clearance is 6-1/4 inches at the lowest point with the Red Line tires installed.
Here’s where Pontiac really excels in the personal car field. The company has gone all-out during the past several years to make a car available for every buyer. Even the trailer folks are catered to, with special towing and braking packages, etc.
Suspension options for the GTO are rather limited, since the car is already well set-up. However, heavy-duty shocks may be purchased. Aluminum front drums and metallic brakes have been mentioned. Special rally wheels are a new twist, made of stamped-steel and vented for brake cooling. They’re nutty.
Powertrain options have been covered, as have engine goodies. Inside, there are a number of things the average good guy would probably want. The full instrument panel is a must. This consists of an excellent electric tachometer with tattle-tale red line, speedo, ammeter, and oil and temperature gages. All these are set in a wood dash insert. A three-spoke dished steering wheel is optional, with a simulated wood plastic rim. Incidentally, the spokes in this wheel have been specifically designed so that all instruments can be read between the spokes—thoughtful, and necessary for a car used in extended competition such as rallies.
And there are added things, like bucket seats with electric adjustment, center consoles, tonneau covers, electric antennae, etc. There’s also a special Bobcat Kit for the engine from Royal Pontiac, which we’ll recap next month. You can get special paint direct from the factory, too, if you order it. There are three basic special equipment forms that pertain to Pontiac, colored red, blue, and green. The red and blue ones apply to the GTO. Check with your dealer for these forms, and look through the GTO brochures, which also contain much of this information.
The gas tank located beneath the trunk holds 21.5 gallons. This particular vehicle registe
Generally speaking, driving this car was a new experience for us. Some of the fellows had driven or owned Pontiacs, but none with all the special equipment this one had.
The first time out to San Fernando dragstrip, a good stiff headwind was blowing and the best performances were in the very low 90s and high 15s. This was in strictly street condition, a condition we maintained throughout the test—carb cleaners on, ignition normal, suspension untouched, etc.
Next we went down to the beautiful new Carlsbad strip, where Jim Nelson let us wail away by ourselves one Saturday. After we made a few runs right on 100 with a best e.t. of 14.86, Nelson couldn’t stand it any longer and came boiling out of the tower to beg a ride. He cranked a best time of 101 mph in 14.65—this still in street trim. We went back to Carlsbad the next weekend after adding Jardine three-port headers installed by Jerry Jardine and some 8.50 M&H cheater slicks. Running 26 pounds of air in the tires and uncorked, speed was up to 102 mph and the e.t. dropped clear to 13.77! Keep in mind that no special tuning had been done on the car, either.
A couple of pointers on this particular car/ engine combination. The hydraulics tend to pump up at about 5,500. If you come off the line at 5 grand, shift to Second at 5,100 and the next two gears at 5,200 for the best results. Of course, these figures can change from strip to strip and between individual cars. We point this out to show the car is getting its best performance below the apparent red line. If you pump the lifters, you can plan on losing at least a half-second.
Nearly everybody dug the handling of this car, even the super-boss brakes. We liked the firm ride, but would opine that things get cramped for us big guys in the back seat. We got about 13 mpg around town, which is good for a Tripower set-up. On the single carb and with the 3.90s in the rear, the little bear would sing along at 92 mph. Then you mashed harder and stuff began happening.
We tried lots of very high-speed panic stops in rapid succession with not a sign of brake fade. But, man, those drums and wheels would blister your hand. The power steering was great after we got use to it, but most of the fellas would prefer the quick-ratio manual steering. Everybody liked the styling, even the girls, who usually classify things as cute or awful. Personally, the only changes we’d make are the addition of more traction at the rear, possibly street slicks (for dry weather, of course), and possibly a flat-tappet cam to get more revs. As a total driving impression, handling the GTO is best described as wild!