In case you haven't heard, GM ran another 69 COPO Camaros for 2013 that offered a slightly different lineup of engines and transmissions. The first run of racers offered three engine combo options: a small supercharger on a 5.3L engine, a larger Whipple blower on the same size 5.3L motor, and a normally aspirated 427 LS engine. For 2013, three engines were again offered, with the only returning engine being the 427. As first released, the two other powerplants were going to be 325hp and 375hp, 396ci LS engines. These were a nod to the original 325hp and 375hp, 396ci big-block Chevy engines offered in the '67 Camaro. The lineup changed slightly on the way back from the NHRA horsepower factor meeting, and by the time the smoke had cleared, the 325hp, 396ci engine combo morphed into a 350hp, 350ci LS engine, effectively lowering the displacement and raising the rated horsepower.
The ’13 COPO cars will come with one of three different normally aspirated engine combinat
The details are what make these combos interesting. The 396ci engine is based on an aluminum LS3 block with its OE 4.065-inch bore and a custom 3.825-inch stroke that computes to an actual 397 ci. This engine features 10.5:1 compression, a big hydraulic roller cam, a Holley tunnel ram with a 90mm throttle body, and all controlled by a Holley HP EFI system. The 350ci engine will employ the more exotic LS7 427 block with its 4.125-inch bore and a really short 3.27-inch stroke that on paper looks like a great bore-stroke combination. This engine will also feature large-port LS3 heads and a similar Holley induction system to the 396ci engine package.
These combos are aimed at NHRA Stock Eliminator racing, and classes are determined by a combination of pounds of vehicle weight per NHRA-rated "factory" horsepower. NHRA also allows a typical combination to add or reduce weight to move between classes. As an example, B/Stock has a factor range of 8.50 to 8.99 pounds per rated horsepower. So if you take 8.50 pounds times 325 hp for the 350ci LS engine, that means the car must weigh (with driver) a minimum of 2,762.5 pounds.
You may have also seen COPO cars, such as Brian Massingill's Camaro or many of the factory-built Mustangs, running AA/-, BB/-, or CC/Stock Automatic. Not that long ago, the top Stock class was A/Stock. But with the supercharged 5.4L Mustangs and '12 COPO 5.3L engine packages, NHRA designated these higher-horsepower cars as AA/, BB/, or CC/. The AA/Stock class, for example, is 6.00 to 6.49 pounds per horsepower. This means that with a 500hp-rated engine at 6.00 pounds per horsepower, a Camaro could weigh as little as 3,000 pounds with a driver. You can see why these cars as so quick, because they are making far more than their factored horsepower yet will weigh right on their minimum.
This is the haps in NHRA Stock Eliminator. If buying a factory-built COPO Camaro is beyond your budget, converting a '10 V6 rental car into a 350ci, LS-powered B/Stock Automatic screamer is certainly feasible. A used '10 V-6 Camaro goes for around $15,000, and that's less than the price of a nice '69 Camaro. There are more and more new cars in Stock and Super Stock every day, and you could be one of them. Check out the action at an NHRA division or national event.
School of Automotive Machinists