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1985 GM M1008 - GI Gyp: Part 6

Performance Bench Seating

John CappaPhotographer, Writer

The seats of your 4x4 are the only component you can change that can lighten your vehicle and make it significantly more comfortable at the same time. After bouncing off of the ceiling of our ’85 Chevy M1008 CUCV military truck nearly every time we go off-road, we decided to address a big part of the problem. Our stock bench seat was worn out and the seat springs were strong enough to send a man into orbit if you hit a bump just right.

In the past, we have had great success with PRP suspension-style seats in several of our project 4x4s. We like the PRP Premier Series seats because they feature deep bolstering that keeps you in place on sidehills and when traversing rough terrain. At the end of the day, the seats make you feel less fatigued because you can concentrate on driving, rather than having to constantly readjust yourself in an unsupportive seat. Think of sitting in PRP suspension seats as sitting in a suction cup. Also, many people with back problems have found that suspension seats, like those from PRP, allow them to return to their 4x4s pain free. Did we mention that PRP seats are typically quite a bit lighter than factory seats and that you can customize your seats with an unbelievable number of fabrics and colors right there on their website? There are enough options to make your head spin, including adjustable headrests, seat heaters, pockets, a water pack, and more.

Even though we love the clamped-in comfort of the Premier Series seats, we also liked having a bench seat to bring along a couple buddies. We could have ordered a large PRP bench seat that fit all the way across the cab of our truck, but we wanted the driver seat to have much more support than the bench seat could provide. So we ordered one Premier Series lowback for the driver side and a 37-inch wide standard lowback bench for the passenger side. Now we get the best of both worlds!

PRP seats come with four welded-on seat tabs. They won’t bolt up to any factory seat mount. However, you have a few options when installing the seats in your 4x4.

If you aren’t much of a fabricator, PRP offers bolt-in seat-mount kits for many of the more popular 4x4s. We weren’t lucky enough to own a popular model, so we had to build our own mounts. We started with the universal PRP angle-bracket kit; it makes mounting a little easier in most cases. Those with full cages can simply incorporate the seats into the cage and purchase small and inexpensive radius weld tabs to complete the install.

Universal slider kits are also available from PRP. They only lift the seat about 1-inch, so they can be added in even the most confined interiors. The sliders are designed to work with the standard PRP seats, but it would not be difficult to modify and adapt them to fit a PRP bench of any width. All you need is a longer transfer wire.

We installed the universal angle brackets on our PRP seats and unceremoniously yanked out the old, battered bench seat. We like to use wood blocks of various sizes to mock the seats in place. This helps to figure out where they are most comfortable and provide the best driver visibility. Be sure to center the driver seat behind the steering wheel and give yourself plenty of headroom. We often tilt our seat mounts rearward as much 15 degrees, depending on the application and visibility. It’s not always possible though, especially in a standard-cab truck like our CUCV. Sometimes we’re lucky to tilt the mounts back 5 degrees.

After some careful measurements, we realized we could use the factory sliders in our installation. A piece of 1-inch, 0.120-wall square tube cut to 521⁄2-inches long was added to the front and back of the original sliding mechanisms. We then cut four 11⁄2-inch-wide, 3⁄16-inch-thick pieces of strap steel to 18 inches. These straps were drilled and bolted to the universal angle brackets on the bottoms of the seats. Once we were happy with the locations of the seats, we tack-welded the straps in place.

We removed the slider assembly for finish welding and painting. The transfer wire across the middle needed to be shortened so the lever would release the catch on both sliders at the same time. We also cleaned and greased the slider assemblies so they worked more smoothly.

After a fresh coat of paint, the slider was once again bolted to the original floor mounts. The slider not only makes it easier for short or tall people to drive the truck, it allows access to storage behind the seat. Our PRP seats do not have a fold-up mechanism, although PRP does offer seats with that feature.

This is a closer look at how we modified the original sliders to work with our PRP seats. Technically, you could bolt all of this together, but welding saved us a lot of time and made the assembly more rigid.

Our 37-inch bench and standard-width seat combo offer us a ton of versatility and comfort. In some cases, the factory seat belts can be reused. They simply slip through the seat slots. PRP bench seats can be ordered in 1-inch increments from 30 to 68-inches wide.