Peterbilt 357/378 Day Cab Conversion

Frequently Asked Questions About Peterbilt 357/378 Day Cab Conversion

What is a day cab conversion kit and why would I need one?

A day cab conversion kit is used to convert a Peterbilt 357 or 378 sleeper truck into a day cab configuration. When the sleeper box is removed, these panels close off the back of the cab, giving the truck a finished, factory-style appearance instead of an open or unfinished rear wall. This is a popular option for owners repurposing a sleeper truck for local or regional hauling where a sleeper is no longer needed.

Will this conversion panel fit my specific truck?

These conversion kits are designed specifically for the Peterbilt 357 and 378 model cabs, but fitment can vary depending on the year of your truck and the specific cab configuration it was built with. Before ordering, check the listed year range and cab style, and compare your truck's rear cab dimensions and mounting points to the product details. If you're unsure, contacting our parts team with your VIN or truck specs can help confirm the correct fit.

What material are these day cab panels made from, and how durable are they?

Day cab conversion panels are typically constructed from aluminum or fiberglass, depending on the specific product. Aluminum panels tend to offer more durability and resistance to cracking, while fiberglass panels can offer a closer factory-style contour. Both materials are built to hold up to daily highway use, but proper sealing and mounting are important to prevent water intrusion over time.

Do these panels come pre-finished, or will I need to paint them?

Most day cab conversion panels are sold unpainted or in a raw/gel-coat finish, meaning you will need to paint them to match your truck's exterior color. This gives you flexibility to match your specific paint code, but it also means you should plan for paint and clear coat work as part of the installation process.

What does installation involve, and can I do it myself?

Installation generally involves removing the sleeper box, trimming or fitting the panel to the rear of the cab, and securing it using rivets, bolts, or adhesive, depending on the kit design. Some fabrication and sealing work is often required to ensure a clean, weather-tight fit. While experienced DIY installers with bodywork experience may be able to complete this themselves, many customers have this done by a body shop or truck upfitter familiar with cab conversions to ensure proper fitment and finish.