The Four Things That Change Exhaust Routing
Exhaust routing length and bend placement shift based on four variables, and they stack on top of each other:
- Cab configuration (regular, extended, crew)
- Bed length (short bed, standard bed, long bed)
- Rear wheel setup (single rear wheel or dually)
- Chassis style (pickup bed versus cab and chassis)
A crew cab short bed truck and a regular cab long bed truck can share the same overall wheelbase on paper, but the pipe still routes differently because the frame layout, fuel tank position, and rear axle offset are not identical between the two body styles.
Quick Self-Check List Before You Order
Before adding a pipe to your cart, pull these details:
- Cab type printed on your build sheet or door jamb sticker
- Bed length in inches, not just "short" or "long"
- Whether your truck is a dually or single rear wheel
- Whether you have a pickup bed or a flatbed/cab and chassis setup
If you can answer all four, fitment confirmation takes a few minutes. If you are missing any of them, jump to the section below on confirming your exact configuration.
Cab Configuration
Regular, Extended, and Crew Cab
Cab length is the first variable that changes routing, because it directly affects where the mid-pipe section starts relative to the transmission crossmember and fuel tank straps.
- Regular cab trucks have the shortest cab-to-axle distance, so the mid-pipe section is typically shorter and the exhaust reaches the axle area sooner.
- Extended cab (SuperCab, Quad Cab, Double Cab depending on the brand) adds length in the middle of the truck, pushing the mid-pipe hangers further back.
- Crew cab trucks have the longest cab, which shifts the entire routing envelope rearward and often requires a longer overall pipe length to reach the same tailpipe exit point.
How Cab Length Shifts the Mid-Pipe Section
The mid-pipe is the section most affected by cab length because it has to clear the transmission crossmember, transfer case (on 4x4 trucks), and driveshaft without contacting any of them at full suspension travel. A pipe built for a regular cab truck will not simply "stretch" to fit a crew cab. The hanger positions, bend angles, and total length are different, which is why platforms like the 6.7 Powerstroke and 6.7 Cummins delete pipe lineups are broken out by exact cab and bed combination rather than sold as one universal length.
Bed Length
Short Bed vs Long Bed Tailpipe Sections
Bed length changes the tailpipe section, which is the part of the exhaust that runs from the rear axle back to the exit point behind the bumper or under the bed.
- Short bed trucks (5.5 to 6.5 feet depending on brand) need a shorter tailpipe run to reach the same relative exit point.
- Long bed trucks (8 feet) need additional pipe length to travel the extra distance between the axle and the rear of the frame.
This is why a 4-inch or 5-inch delete pipe built for a short bed 6.7 Powerstroke will come up short on a long bed truck, even though the diameter and material are identical. The diameter question (4-inch versus 5-inch) is a separate decision from length, and it is worth reviewing on its own once you have your cab and bed configuration locked in.
Dually vs Single Rear Wheel
Exit Routing and Tip Clearance
Dually trucks (dual rear wheel, or DRW) and single rear wheel (SRW) trucks share the same frame rails in many cases, but the rear wheel width changes where the exhaust tip can safely exit without contacting the tire or fender.
- SRW trucks typically route the tailpipe closer to the centerline or exit just inside a single rear tire.
- Dually trucks need the exhaust routed further inboard or exit between the dual wheels, since the tip position on an SRW-spec pipe would land directly under the outer dual tire on a DRW truck.
If you are unsure which category your truck falls into, check your rear axle. Dually trucks have four rear wheels total (two on each side); SRW trucks have two.
Chassis Cab and Cab-and-Chassis Trucks
Cab and chassis trucks (no factory pickup bed, often fitted with a flatbed, dump body, or utility body) are a separate category entirely. These trucks do not have the same frame length or fuel tank position as a pickup bed truck of the same cab type, so pipes built for pickup applications generally will not fit cab and chassis trucks correctly. If your truck started life as a cab and chassis or has had the bed replaced with an aftermarket flatbed, check listings specifically labeled for cab and chassis fitment, or contact support with your build details before ordering.
When Configuration Doesn't Matter
Kits That Stop Before the Variable Section
Not every product on your truck is affected by cab and bed length. Some kits, like EGR delete kits or up-pipe components, live entirely in the engine bay or turbo area, well ahead of the sections that change with cab and bed configuration. These parts are typically fit by engine platform and model year alone, not by body style.
The parts that do depend on cab and bed configuration are the ones that physically run the length of the frame: downpipe-back exhaust systems, mid-pipes, and tailpipe sections. If you are only replacing a component ahead of the mid-pipe, cab and bed length usually will not factor into your fitment decision.
How to Confirm Your Exact Configuration
Door Jamb Sticker and VIN Decode
The fastest way to confirm your exact setup is the certification label on the driver's door jamb. This sticker lists your GVWR, tire specs, and often a body code that identifies cab type and bed length. If the sticker is worn or missing, your 17-digit VIN can be decoded through the manufacturer or a VIN decoder tool, which will return your cab configuration, bed length, and drivetrain in a few seconds.
Measuring Wheelbase as a Fallback
If you cannot access a VIN decode, measuring your wheelbase (center of front wheel to center of rear wheel, in a straight line) will narrow down your configuration. Manufacturers publish wheelbase specs by cab and bed combination, so a measured wheelbase can be cross-referenced against those published numbers to identify your exact setup.
What to Send Support If You're Still Unsure
If you have checked the door sticker, tried a VIN decode, and you are still not confident in your configuration, send our support team the following before ordering:
- Year, make, and model
- Engine (6.7 Power Stroke, 6.7 Cummins, Duramax, etc.)
- Cab type and bed length from the door sticker if visible
- Whether the truck is dually or single rear wheel
- Photos of the current exhaust setup if it has already been modified
This lets us confirm fitment before you buy instead of after a return request. Diesel platforms like Duramax delete pipe applications have several LML, LBZ, and L5P body style combinations, so a quick check before ordering saves a step later.
FAQ
Does a longer bed always mean a longer delete pipe? Usually yes, since bed length changes the distance the tailpipe section has to travel to reach the same relative exit point. Bed length is not the only variable, so confirm cab configuration and rear wheel setup as well.
Can I cut a pipe down to fit a shorter configuration? Some installers can modify pipe length with proper tools and experience, but this is not the recommended approach for buyers without exhaust fabrication experience. Ordering the correct length for your configuration avoids modification and keeps hanger positions where they were designed to sit.
Will a regular cab pipe fit if I only care about length, not hanger position? Length alone is not enough to confirm fitment. Hanger positions are built around the frame crossmembers and body mounts specific to each cab and bed combination, so a pipe that happens to be the right length may still not hang correctly.
Does this apply to gas trucks too, or just diesel? This guide is written for diesel platforms (Power Stroke, Cummins, Duramax) where downpipe-back exhaust and delete pipe products are cab and bed specific. Gas truck exhaust systems follow similar routing logic, but product availability and configuration breakouts differ by platform.
Is a delete pipe legal to install on my truck? Some emissions-related exhaust products are intended only for off-road, race, or non-public-road use where permitted. Customers are responsible for confirming compliance with federal, state, and local laws before purchase and installation. Check your local regulations before deciding whether this product fits your intended use.
For a closer look at how pipe diameter and muffler choice factor into the decision once you have your cab and bed configuration confirmed, our guides on delete pipe versus full delete kit for the 6.7 Cummins and the 6.7 Powerstroke delete pipe versus full delete kit comparison walk through the next decision point. Duramax owners comparing DPF-only removal against a full setup can also check the L5P DPF delete pipe buyer's guide.
Cab and bed configuration is not a small detail on a delete pipe purchase. It is one of the four core variables that determines whether the part you order will hang correctly the first time. Shop delete pipes with fitment filters built around exact cab, bed, and drivetrain combinations, or send your truck details to support before you order if you are still working out your exact setup.
