Frequently Asked Questions About Kenworth W900A Exhaust Kits

What years of Kenworth W900A trucks are these exhaust kits compatible with?

Our exhaust kits are designed to fit Kenworth W900A models from 1961 through 1985. However, compatibility can vary based on your specific truck configuration, wheelbase, and any modifications made over the years. We recommend checking your truck's exact specifications or contacting our support team with your VIN to ensure proper fitment before ordering.

Are these exhaust kits made from stainless steel or aluminized steel, and which is better for my truck?

We offer both stainless steel and aluminized steel options. Stainless steel kits (typically 409 or 304 grade) provide superior corrosion resistance and longevity, lasting 10-15 years on average. Aluminized steel kits are more budget-friendly and still offer good durability of 5-7 years under normal conditions. Choose stainless if you operate in harsh weather conditions or want maximum longevity. Aluminized works well for mild climates and regular highway use.

Can I install these exhaust kits myself, or do I need professional installation?

Installation difficulty varies by kit type. Straight pipe replacements can typically be installed by experienced DIYers with basic tools, requiring 2-4 hours. However, complete turbo-back systems or kits requiring new hangers and brackets often need welding and professional alignment. Most customers report needing a sawzall for removing old pipes, proper jack stands, and penetrating oil for rusted bolts. Professional installation typically runs $200-500 depending on complexity.

What diameter exhaust pipes work best for W900A trucks, and will larger pipes improve performance?

Most W900A trucks came factory with 5-inch exhaust systems, which remains the most popular replacement size. While 6-inch and 7-inch options are available, larger diameters don't automatically mean better performance. For stock or mildly modified engines under 500 HP, 5-inch provides optimal exhaust velocity. Engines over 500 HP or with significant modifications may benefit from 6-inch pipes. Going too large can actually reduce low-end torque and exhaust brake effectiveness.

Do these exhaust kits include mufflers, and how much will they change my truck's sound level?

Kit contents vary by model - some include mufflers while others are muffler-delete or straight pipe configurations. Kits with performance mufflers typically increase sound by 3-7 decibels over stock, creating a deeper tone without excessive drone. Straight pipe kits can increase sound by 10-15 decibels, which may exceed legal limits in some states. Check your local noise ordinances before selecting a kit. We clearly specify muffler inclusion and expected sound levels in each product description.