Frequently Asked Questions About Freightliner FLT Cabover Chrome Stacks & Tops

What diameter stacks are compatible with my Freightliner FLT cabover, and how do I measure correctly?

Most Freightliner FLT cabovers use 5-inch diameter exhaust systems, but some models may have 6-inch or 7-inch configurations. 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 6 inches down from the top of your current stack for accuracy. If you're between sizes, always round down and use an adapter if needed. Common FLT models from 1984-1991 typically use 5-inch stacks, while some heavy-haul configurations may require larger diameters.

Will these chrome stacks fit my specific year FLT model, and are there any mounting differences I should know about?

Our chrome stacks are designed to fit Freightliner FLT cabovers from 1978 through 1991, including FLT086, FLT104, and FLT120 models. The main mounting difference occurs between pre-1984 and post-1984 models due to cab design changes. Earlier models may require additional bracket modifications for proper alignment. All stacks come with universal mounting clamps, but vehicles with aftermarket air cleaners or modified exhaust routing may need custom brackets. We recommend checking your frame-to-cab clearance before ordering stacks longer than 48 inches.

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

Installation typically takes 2-3 hours per stack for someone with basic mechanical skills. You'll need a socket set (typically 9/16" and 5/8"), penetrating oil for rusted connections, a rubber mallet, and exhaust sealant. The most challenging part is usually removing old, corroded stacks - apply penetrating oil 24 hours before starting. New installations require loosening the exhaust clamp, removing the old stack, cleaning the connection point, applying high-temp sealant, and sliding the new stack into place. Ensure at least 3 inches of overlap for a secure fit. Some installers prefer using a strap wrench to avoid scratching the chrome during final positioning.

What's the difference between 304 and 430 stainless steel stacks, and which chrome finish lasts longer?

304 stainless steel stacks offer superior corrosion resistance and typically maintain their chrome finish for 5-7 years with proper care. They contain nickel, making them non-magnetic and more resistant to road salt and chemicals. 430 stainless stacks are magnetic, more affordable, and generally last 3-5 years before showing signs of rust or pitting. For maximum longevity, choose triple-chrome plated 304 stainless. The chrome plating process matters as much as the base material - look for stacks with copper and nickel base layers under the chrome. Regular polishing with chrome-specific products every 2-3 months significantly extends the finish life regardless of material.

What stack styles work best for FLT cabovers, and do I need heat shields?

Straight stacks and curved stacks are the most popular for FLT cabovers. Straight stacks provide a classic look and are easier to install, while curved stacks direct exhaust away from the cab and trailer. Miter-cut tops are preferred over turn-out tops for cabovers due to height restrictions. Heat shields are strongly recommended if your stacks pass within 12 inches of the cab, sleeper, or any wiring harnesses. West Coast-style stacks (with expanded ends) work well on FLTs but may require trimming for proper door clearance. Bull hauler stacks look impressive but can create clearance issues with low bridges - keep total height under 13'6" for standard routes.