Frequently Asked Questions About Peterbilt 359 Engine & Performance Parts
Will these performance parts fit my specific year Peterbilt 359?
Most engine and performance parts for the Peterbilt 359 are compatible across the entire production run from 1967 to 1987. However, there are important exceptions. Early models (1967-1972) with naturally aspirated engines may require different turbo installation kits than later models. Always verify your engine model (CAT 3406, Cummins NTC, or Detroit Diesel) before ordering, as mounting brackets and connections can vary. We recommend checking your OEM or calling our tech support with your truck's serial number for exact fitment confirmation.
What kind of horsepower gains can I realistically expect from upgrading my 359?
Realistic power gains depend on your starting engine configuration and the parts you choose. A basic air filter and exhaust upgrade typically yields 15-30 HP. Adding a performance turbo to a naturally aspirated engine can increase power by 75-150 HP. Complete engine rebuild kits with performance pistons, cam, and injectors can push gains to 200+ HP over stock. Keep in mind that significant power increases require supporting modifications like upgraded cooling systems and may affect reliability if not properly tuned.
Are aftermarket parts as reliable as OEM for my classic 359?
Quality aftermarket parts from reputable manufacturers like PAI, Interstate-McBee, and FP Diesel often match or exceed OEM specifications, especially since many original Peterbilt parts are no longer in production. Look for parts that meet or exceed OEM standards and come with warranties. Critical components like head gaskets, bearings, and injectors should always be sourced from established brands. Avoid extremely cheap alternatives, as the cost savings rarely justify the risk of premature failure in a working truck.
Can I install these performance parts myself, or do I need a shop?
Basic upgrades like air filters, exhaust tips, and gauges can be installed by mechanically inclined owners with standard tools. However, internal engine components, turbo installations, and injection pump adjustments require specialized knowledge and tools. Improper installation of performance cams, pistons, or turbochargers can cause catastrophic engine damage. Most customers find it cost-effective to install external bolt-on parts themselves while leaving internal engine work to experienced diesel mechanics familiar with older Peterbilt systems.
How do performance modifications affect my 359's fuel economy?
The impact on fuel economy varies significantly based on the modifications and how you drive. Properly tuned performance air intakes and free-flowing exhausts can improve fuel economy by 5-10% under normal driving conditions. However, aggressive cam profiles and larger injectors typically decrease fuel economy by 10-20% or more. Turbo additions to naturally aspirated engines often improve loaded fuel economy but may slightly decrease empty mileage. The key is proper tuning - a well-tuned performance engine can maintain reasonable fuel consumption while delivering more power when needed.
