These 5 factory-built Pontiac sleepers are riots under the radar

In the world of performance cars a “sleeper” car can be best defined as a car that has all the outward appearances of a standard or base model car, but with added performance. Essentially all go and no show. Even before the introduction of the GTO in 1964, Pontiac had already established itself as a force to be reckoned with on the street and track. This reputation ebbed and flowed in the following decades until its unfortunate demise in 2010. While there are worthy cars not included in this list, we’ve selected five of Pontiac’s best sleepers to hit the streets.

1960-1963 Pontiac Catalina Super Duty

Following a significant rebranding in the late 50s, Pontiac head, Semon “Bunkie” Knudsen was working to market the struggling brand to a more youthful buyer. The obvious choice was to reinvent the company as the provider of absolute performance. With Pontiac’s success on the NASCAR circuit and on the drag strip, its popularity soared and with homologation rules, all the parts used had to be available over the counter and actual production cars had to be built for public sale.

At the time, the popular platform for racing was the stripped-down Catalina (Grand Prix as well in limited quantities). In 1960, the Super Duty package got you a 389 upgraded with forged internals, solid lifter camshaft, aluminum intake and high flow exhaust manifolds. The early 389-powered cars had 348 hp with the 4bbl, the Tri-Power cars had 368 hp. In late 1961, a 373-hp 421-cubic-inch motor came out as a response to the Ford 406, Chevy 409, and Chrysler 413, although in limited quantities as a dealer- or owner-installed option.

By the time GM banned corporate-sponsored racing in 1963, the ultimate Super Duty Catalina was available with a 421 making a conservative 405 hp, alloy body panels, and a “Swiss cheese” frame for further weight reduction. Only a handful of these were ever produced; the majority were steel-bodied beasts with the upgraded engine. Many of these cars competed in Super Stock class racing. Street driving was not exactly practical, but they were still street-legal.

Because these cars were meant to be as basic as possible for weight savings, there were no flashy frills that might hint at ETs in the low 12s when fully optioned with the lightweight bits. Not bad for a 17 ½-foot-long behemoth. The Super Duty Catalinas are some of the first understated performance cars offered by Pontiac, and certainly an icon of pre-GTO Pontiac performance.

1970-1971 Pontiac GT-37

The GT-37 is perhaps one of the best kept performance secrets among Pontiac enthusiasts. If you wanted a GTO but couldn’t afford one or just didn’t want the attention, the GT-37 was the car for you.

Introduced mid-year 1970 and based off of the bare-bones T-37, you could enhance your car into a GT-37. Choosing this option got you GTO dual exhaust, Rally II wheels, hood pins, GT-37 badging and graphics as well as a standard floor-shifted three-speed transmission mated to a 350-cu-in 2bbl engine. You could stop there and live happily or you could upgrade to a four-speed and a 330-hp 400 engine in 1970.

When 1971 rolled around this offering cranked up to the beastly 455 HO (high output). Essentially, you could order yourself a GTO Judge without all the Judge frills, which saved you several hundred pounds of weight. In drag racing terms, that’s a few tenths of a second dropped off of your ET. In a world with high-impact colors, flashy stripes and shaker hood scoops, the GT-37 was a subtle infiltrator to the muscle car ranks that could easily hang with or dominate its more expensive competitors. If in 1971, you just bought yourself a brand-new GTO Judge and lined up against a GT-37 on Woodward Ave, you did not enjoy the free can of butt-whooping it handed to you.

1969-1972 Pontiac Grand Prix

While the personal luxury market was no new thing—the Thunderbird, Riviera, and Toronado were pioneers in the field—the Grand Prix redefined the market. Under the direction of John Z. DeLorean, Pontiac developed this sporty new luxury car on their new G-body platform. (This was essentially a variant of the preexisting A-body platform.) The new platform had fresh looks and a cockpit-style interior that was an instant hit, boosting sales from around 30,000 for 1968’s full-size Grand Prix to well over 100,000.

Revolutionary styling aside, where the Grand Prix really shines is in performance. In true Pontiac fashion, comfortable digs didn’t mean it had to be slow. The base “Model J” came with a 400-cu-in V-8 making 350 hp—the same base engine as the GTO. Because it wasn’t the A-body, which had a 400-cubic-inch size limit imposed by GM (potentially a deliberate side step by DeLorean) the “Model SJ” package came standard with a 428. That was good for 370 hp, not to to mention the 390-hp HO version.

While few opted for it, a close-ratio four-speed manual transmission was also available for those who wanted to row gears in style. 1970 had the same base engine, but the SJ was offered with the all-new 455 that made 370 hp. As the 1970 Grand Prix brochure read “We don’t build a ‘luxury’ car. We build a performance car then we make it luxurious.” If you were willing to spend a little more, you could send your 1970 and later Grand Prix to Hurst for its SSJ package, adding even more amenities and performance options.

Like with any car from the era, ‘69-’70 Grand Prix are considered the pinnacle years for performance, although the ‘71-’72 are also potent. If you want a car that is well-equipped, goes like hell, and completely flies under the radar, the Grand Prix is for you. Just be prepared to explain to the casual enthusiast that your car isn’t from the mid-’70s, it isn’t a Monte Carlo, and it is indeed fast.

1991-92 Pontiac Firebird SLP Firehawk

While the 1993-2002 Firehawks are the best known creations by Firebird tuners Street Legal Performance (SLP), the roots of the Firehawk go back to the final years of the third-generation Firebird.

For the latter end of 1991 and 1992, SLP set out to make the ultimate third-gen Firebird. Starting with a basic Firebird Formula, SLP dropped in a highly warmed over 350-cu-in V-8 making 350 hp, a six-speed ZF transmission out of the Corvette, upgraded Dana 44 rear axle, and, if you ordered the competition package, you were also treated to a set of Brembo F40 front brakes.

The exterior remained untouched, giving the appearance of a standard Firebird Formula. Capable of going 0-60 in only 4.6 seconds and just as savage when cornering, this car was intended to be a serious track weapon. To pick one up, all you had to do was walk into your local Pontiac dealer and asked for the B4U package, and soon enjoy the Firehawk delivered to you at a hefty price of $40,000 (that’s about $73,000 in today’s money).

Only 26 Firehawks were produced before the switch to the fourth-generation Firebird. Because of their rarity and unassuming looks, these cars aren’t often talked about outside of Firehawk groups. If the average person ran into one of these cars, chances are they wouldn’t know what they are looking at. The downside is that the low production numbers and high collectability among Pontiac fans means that running across one outside of someone’s collection is very slim.

2008-2009 Pontiac G8 GT/GXP

After the moderate success of the Holden Monaro-based GTO, Pontiac brought over another muscle car from Australia for us to enjoy. Based off Holden’s VE Commodore, the G8 was a rear-wheel drive sports sedan which came to the U.S. from 2008 to 2009, just before Pontiac closed its doors for good.

While there was a base V-6 option, the GT and GXP options offered two levels of V-8 performance. The GT received the 361-hp, 6.0-liter L76 V-8 and was only available with a six-speed automatic transmission. In 2009 you could opt for a G8 GXP, which boasted meaty power from a 415-hp LS3 V-8 engine and an optional six-speed manual transmission. If that wasn’t enough, 24 people opted to order the SLP-tuned G8 Firehawk through their dealers, which upgraded the GT or GXP with a supercharger and output in excess of 500 hp.

Because the G8 is simply a badge-engineered Holden, bold styling isn’t its strong suit. A G8 is easily mistaken for a number of other cars in the Pontiac line, and the alphanumeric naming system that Pontiac used in the final days didn’t suggest the G8 was anything more than an enlarged G6. But for those crafty individuals seeking a subtle four-door family sedan that didn’t want to pay for a CTS-V or follow the masses and buy a Charger, picking up a G8 was a no-brainer.

Bonus: 2005-2008 Pontiac Grand Prix GXP

Yes, you read that correctly. A front-wheel drive sedan worthy of being mentioned even at the bottom of this list, because this Grand Prix has a 303-hp 5.3-liter V-8 wedged under the hood.

Towards the end of Pontiac’s existence, GM had grown accustomed to sending power to the wrong wheels on most of its passenger cars. So at this point, why not shove a made-to-fit version of the LS small-block under the hood? After all, the supercharged 3.8-liter GTP variants had some success, so go big or go home right?

This odd combination made for a surprisingly quick car that could sprint from 0-60 in 5.6 seconds. With this level of performance there came some downsides, as expected. Torque steer during acceleration was real, along with concerns that the transaxle wasn’t up to the task of handling the torque of a V-8, and the W-platform had been around too long and was starting to show its age.

The biggest boon for the Grand Prix GXP is that nobody will see it coming. This style of Grand Prix is still a fairly common car and there are no obvious ways of differentiating the GXP form the standard models aside from the subtle badging. Add that together and you have a car which flies completely under the radar, even among auto enthusiasts. Whether or not this car was a good idea remains a debate for another day and another space, but the Grand Prix GXP is absolutely a sleeper.