Duel Exhaust
Grandson wants to install duel exhaust on his 08 GMC Sierra 5.3L engine. Any drawbacks to this or is there an upside. I've heard both. With the valve overlap and less back pressure you lose low end to...
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It won't hurt a thing. He might lose some lower end torque, but will pick up hp at the upper end. Plus it's fun. If he doesn't like it, he can always change it back to stock. He's a kid, let him play.
