The installation process began by cutting the stock "Y" pipe into a "dual" configuration. The chain cutter (shown here) made short work of the FoMoCo metal.	Following the factory route, we ran the exhaust down the passenger frame rail. This eliminated any chance of front driveshaft/transfer case clearance problems.

Quick Facts The SpinTech approach to muffler design is unique, to put it mildly. To be blunt, it's one of those things that make you scratch your head and say to yourself "What the #%&! were they thinking?" In general, they were thinking about performance. SpinTech produces a wide variety of mufflers sized and tuned to handle everything from mild street stockers, to cruisers, to balls out drag and Winston Cup cars. Available in traditional round and oval inlet / exhaust configurations, these fabricated mufflers are available for about any application and horsepower level you can imagine.

The original "Y" pipe was constructed of stout tubing, and eliminated the need to start from scratch. At 2 1/4 in., we have consistent pipe diameter from manifold to exhaust tip. No one felt that a larger tail section would yield any tangible benefit on the mild engine.	Unlike an exhaust system from a volume muffler shop, these tubes are cut and welded to form a restriction free flow path. Said Armando, "This is the right way to do it." It's a more time and labor intensive process, but the ultimate results are worth it.

Quality Under Control When the magical UPS truck arrived with our new mufflers, I was amazed at the sheer weight of the product. Figuring there was additional hardware enclosed, I opened the box to find that such was not the case. Using 16-gauge steel, the SpinTech mufflers are about as close to bullet proof as a muffler can get. In fact, as the guys at Hot Cars, Cool Trucks began fabricating the custom exhaust system that would soon feed them, we all contemplated using them as a skid plate. Yes, they are that rugged, but I'm getting a little ahead of myself.

The pure beef of the SpinTech mufflers is something to behold. With a 16 gauge fabricated shell and welded construction, you'll be hard pressed to do them much damage. To simplify our installation the two mufflers were welded together, resulting in less movement in the exhaust system and minimizing the potential for cracked pipes down the line.	Once the welds cooled, the SpinTechs were moved into place and work began to mate them to the manifolds. Be sure to allow enough clearance near the frame and the driveshaft. While the frame may not move much, the rear shaft will move laterally under extreme articulation. That movement could lead to major component damage, depending on the degree of movement involved.

Since headers weren't on the agenda for this installation, but are coming in the future, Armando tapped into the factory "Y" pipe and began the process for tucking the pipes up and out of the way. Step by step, the exhaust system began to take shape, and soon, Armando had mounted and connected the SpinTechs to the frame. Here too, the pride in workmanship became apparent. Rather than use part store hangars, "L" brackets with urethane bushings were attached to the frame via welded studs, and in turn, were welded to the muffler body. That's the nice thing about 16 gauge steel - you can weld, and repair it, should either become necessary.

Try that with a $19.95 special! We'd chosen to exit the exhaust before the rear passenger wheel, simplifying the installation considerably, and leaving the rear axle area open for future suspension modification. CJ had informed us earlier that the 3221's were originally a "race" muffler, but proved to be too quiet to be popular. Shifting gears, SpinTech has since moved the 3221 into the street category, where it found it's true calling. "It has a little growl to it, but it's nothing like a Flowmaster," said CJ, "They're as different as night and day."

With short'ish 2 foot "tail pipes" coming out the back, I'd assumed that the noise level would rise considerably. If all else fails, I thought, I can always go to a longer pipe, run out the back. Much to my surprise, that would prove to be unnecessary.

When it comes to positioning components, the F-trucks have plenty of room to work with. Depending on your needs, SpinTech mufflers can be ordered with any combination of inlet/outlet positioning. You aren't limited to what someone else thinks you need. In our case, a dual center arrangement was the hot setup.	Once fitted into their final position, the inlet pipes were attached and work began on the tail pipes. While we chose a front of the tire exit for simplicity, a rear exit system would allow for a completely hidden (and protected) mufflers. Fortunately, these units are tough enough to absorb ridiculous amounts of punishment.

Backpressure? As we pulled away from Hot Cars, Cool Trucks, it was immediately apparent that the combination of Armando's fabwork, and SpinTech's mufflers had freed up several horsepower. While we haven't a dyno handy to give exact figures, I don't think it's a stretch to say that 20 or so fresh ponies would be far off the mark. The new motor felt much more responsive, and you could feel the newfound power from idle, well up into the 5500 RPM range. Unfortunately, we cannot tell you at this time what the mileage differential will be, as we've had less than 100 miles on the new system. However, as a totally unscientific guesstimate, It took a little over a quarter tank of gas to get to the shop, and a little under a quarter tank to get home.

As with the rest of the exhaust, the dual outlets were custom fit and fabricated. Hand fitting the pieces resulted in a symmetrical outlet, and no restriction to flow as the exhaust exits the system.	Putting the final touches on the system, Armando ensured a rattle-free installation by welding the outlets together and mounting them with urethane bushed "L" brackets.