Peterbilt 357/378 Chrome Stacks & Tops

Frequently Asked Questions About Peterbilt 357/378 Chrome Stacks & Tops

What exactly are exhaust stacks and tops, and will these fit my Peterbilt 357 or 378?

Exhaust stacks are the vertical exhaust pipes that route exhaust gases up and away from the cab, while stack tops (also called exhaust tips or rain caps) are the decorative and functional caps that fit on top of the stack. This category includes chrome stacks and tops designed to fit the Peterbilt 357 and 378 models. Because stack diameter and length can vary by truck configuration, always check the listed dimensions against your current exhaust setup before ordering.

What is the difference between a straight stack top and a curved or turned-down top?

Straight tops maintain a vertical exhaust flow and are common for a classic stack look, while curved or turned-down tops angle the exhaust outward or downward, which some drivers prefer for keeping exhaust and soot off the trailer or cab. The choice is largely about appearance and personal preference, though you should confirm your stack top choice does not violate any state or local regulations regarding exhaust direction.

What material are these stacks and tops made from, and how do I keep the chrome looking good?

These products are typically constructed from chrome-plated steel or stainless steel with a chrome finish, giving them a bright, reflective look. To maintain the chrome finish and prevent pitting or rust, regular washing with mild soap and water is recommended, along with periodic application of a chrome polish, especially in areas with road salt or heavy weather exposure.

Can I install these stacks and tops myself, or do I need a professional?

Many stack tops are a simple slip-on or clamp-on fit over the existing exhaust pipe and can be installed with basic tools in a driveway or shop setting. Full stack replacements that involve modifying or replacing exhaust piping are more involved and may require welding, brackets, or exhaust system knowledge, so those installations are often best handled by a qualified diesel technician.

Will adding a stack or top affect my exhaust flow or engine performance?

Stock-diameter replacement stacks and tops that match your original exhaust dimensions typically have minimal impact on exhaust flow or performance. However, choosing a top with a significantly different diameter or a restrictive design could affect backpressure, so it is a good idea to match the inside diameter of the top to your existing stack unless you have specifically researched a performance change.