Sound Advice

Hooker offers everything that’s needed to add a performance exhaust system. For our ’72 Nova, we chose a set of Hooker Competition headers, a pair of Hooker Aero Chamber mufflers, and a dual-exhaust kit.

With this cutting tool, available from many tool stores, the existing exhaust system can easily be removed.

With the pipes cut, the factory transverse muffler only needed the hangers unbolted for removal. To remove the head pipes from the exhaust manifolds, spray liquid penetrant onto the studs and remove the three nuts from each side with a deep 9/16-inch socket. Remember to support the car on jackstands when working underneath.

To remove the exhaust manifolds, first place a drain pan under the engine, drain the coolant, and remove any temperature sending units. Next remove all spark plug wires and spark plugs.

Next unbolt both cast-iron exhaust manifolds...

...and spark plug wire heat shields from the cylinder heads.

Before installing the headers, make certain that the gasket mounting surface and threaded holes are clean. The oil dipstick tube will also need to be removed to clear the header flange.

Installing the left-side header required the Nova to be several feet off the ground. Remember to have the vehicle safely on jackstands with the rear tires blocked. With a friend’s help, we installed the header up from underneath. On some installations, the motor mount may need to be loosened to raise the engine and gain additional clearance. On our ’72 Nova, the headers could be installed without loosening the motor mounts. The passenger-side header installed easily through the top of the engine compartment.

On our Nova, the pipe for the No. 3 cylinder touched the steering box. Since this would cause a vibration, we marked the contact area with a felt pen and removed the header. Then with a hammer and a suitable size of galvanized pipe, we dimpled the header tube to allow for clearance.

Remember to check that the attaching bolts and spark plug boots will clear each header pipe. Sometimes an old cylinder head can be used to mock up the installation. Remember to include header gaskets when checking clearance. Both our headers required minor dimpling...

...for bolts and spark plug boot clearance.

With each header installed, check for adequate clearance between the pipes, engine, and chassis.

To help with the dual-exhaust system installation, we contacted the folks at Kenz Muffler in Oxnard, California. Although this kit is designed as a bolt-in, we wanted to have it welded in place and fitted for optimum clearance.

First, Jeff Clark at Kenz Muffler test-fitted the head pipes for clearance.

Since these pipes are designed to fit ’68 to ’79 Novas and second-generation Camaros, some minor tweaking was necessary for clearance.

Next, Jeff positioned the Aero Chamber mufflers to the head pipes.

When positioning the tailpipes, be certain that there is adequate tire clearance...

...and the tail pipe exits without hitting leaf springs or sheetmetal.

To dampen the exhaust pulses, we opted to have Keith Griffin at Kenz Muffler install an H-pipe.

With everything welded up, the Hooker exhaust system looks and sounds great. Remember to retighten all header bolts daily (with the engine cold) for at least one week after installation. This allows the header gaskets to seat and minimizes the chance of future exhaust leaks. With the engine able to breathe better, our future performance upgrades will really perform.

Running in the Los Angeles Marathon requires endurance, proper training, the will to finish—and most of all, the ability to breathe. As fundamental as that may sound, a high-performance engine makes similar demands. Since an engine is simply an air pump, improving its performance requires a good-flowing exhaust system. Stock exhaust manifolds work fine for stock performance, but raising that performance bar requires installing free-flowing headers and a performance exhaust system.

Since our test Nova is scheduled for a performance buildup with Holley’s Avenger package, it needed a performance exhaust system. So follow along as we show you how straightforward installing headers and a high-performance exhaust system can be. You’ll breathe easier.