Frequently Asked Questions About Peterbilt 389 Chrome Stacks & Tops

What size exhaust stacks fit my Peterbilt 389, and how do I measure for the correct diameter?

Most Peterbilt 389 models use 5-inch or 6-inch diameter exhaust stacks, with 5-inch being the most common. To measure correctly, use a tape measure to find the outside diameter of your existing exhaust pipe where the stack will connect. Measure at least 3 inches down from the top for accuracy. If you're upgrading from a different size, you'll need the appropriate reducer or adapter. For DPF-equipped trucks (2008 and newer), ensure the stack accommodates your aftertreatment system's requirements.

Will these chrome stacks work with my 2008-2023 Peterbilt 389's emissions equipment?

Yes, our chrome stacks are compatible with DPF and DEF-equipped Peterbilt 389 trucks from 2008-2023. However, you'll need to select stacks specifically designed for emissions-compliant systems. These feature proper heat ratings and mounting configurations that work with your existing exhaust aftertreatment components. Pre-2007 models without emissions equipment have more flexibility in stack selection. Always verify your truck's specific year and emissions configuration before ordering.

How difficult is the installation, and what tools do I need?

Installation typically takes 2-4 hours and requires basic hand tools including socket wrenches, band clamp tools, and potentially a drill for bracket mounting. Most installations involve removing the old stack, cleaning the connection point, and securing the new stack with heavy-duty clamps. The main challenges include aligning tall stacks properly and ensuring adequate clearance from cab components. We recommend having a helper for stacks over 48 inches tall. Professional installation runs $150-300 if you prefer expert mounting.

What's the difference between mirror-polished and standard chrome finish?

Standard chrome finish provides excellent shine and durability for most applications, featuring a bright, reflective surface that resists corrosion. Mirror-polished chrome undergoes additional buffing processes to achieve an ultra-reflective, show-quality finish with minimal surface imperfections. Mirror polish typically costs 20-30% more but offers superior appearance for show trucks. Both finishes require regular maintenance with chrome polish to prevent pitting and water spots, especially in harsh weather conditions.

Do curved or straight stacks affect my truck's performance or sound?

The shape primarily affects aesthetics and sound direction rather than engine performance. Straight stacks produce a more direct, louder exhaust note that projects upward. Curved stacks angle the exhaust away from the cab, reducing in-cab noise levels by 3-5 decibels and directing soot away from your trailer. Miter-cut tops further alter sound characteristics, creating a deeper tone. Neither style significantly impacts horsepower or fuel economy when properly sized for your engine's requirements.