Project Big Bad Chevy

Like most older trucks, ours started life as a diesel work horse. The previous owner did quite a few modifications to make the truck more off-road friendly. One of the first modifications was to remove the tired diesel engine and transmission and install a very healthy Chevy 383 engine and 750 Holley carburetor matted to a stock NP208 transfer case and a built TCI TH350 transmission. He also installed a mild lift, a step side bed with a rotted wood floor, and Weld wheels with 35 inch BFG mud terrain tires. The OEM saddle fuel tanks were removed and a Ford van fuel tank was installed in the rear of the chassis. The final modification was to slap a cheap coat of red paint on the body.

The day after we bought it, we took it out on some local mountain trails for a test run. We quickly realized that this truck needed some help to make it a comfortable and dependable off-road toy. Just driving it to our destination on the freeway we found it to ride like a tank and it was very noisy in the cab from the worn out door and window seals. Once we hit the trail we found that the 35” tires would rub on the front and rear fenders when the suspension was flexed, so much so that it took a few chunks of tread off of a couple of the tires.

We also quickly noticed that the carburetor likes to flood and stall the motor on bumpy roads. This is not a good thing to have happen while heading down a steep decent because of the loss of the power brakes and steering! As for the stock steering, we found that it’s pretty much useless trying to maneuver over obstacles at slow speeds with the suspension flexed to its limit.

This test run turned out to be a challenge of driving skill with trying to keep the motor revved enough to not stall while maneuvering over obstacles with poor steering. On the drive home our list of modifications grew quite a bit!

We first wanted to fix the minor issues and change most of the fluids. First on the list was the stalling issue and after some research we found that an easy fix for the carburetor is to install a spring kit in the needles to keep the floats from bouncing around so much along with connecting the vent tubes using a piece of rubber hose with a small hole cut in the center. This made a drastic difference with our stalling issue but we found it didn’t completely eliminate the problem. To address the fender rubbing issue we did a simple trim of the fenders with a cut off wheel. It’s certainly not the cleanest cutting job we have seen but it is very functional.

While crawling around under the truck made a few more discoveries. We found the transmission and the transfer case both had leaks and the transfer case rubber mounts felt like Jell-O! We installed a new transmission pan and filled it with fluid. However, our transmission leak was worse! Upon closer inspection we found that the previous owner did not properly secure the transmission dip-stick housing and it was flopping around which was causing a bad leak where the dipstick goes into the transmission. A couple o-rings and a decent amount of RTV gasket sealer cured this problem. For the transfer case, we topped it off with fluid, ordered new mounts and called it good for now.

The next quick fix we decided to conquer was the installation of an emergency brake. While trying to figure out what parts we needed to complete this part of the project, we made another startling discovery. Usually the brackets that hold the brake cables that come out of the rear brake drums are 12 or more inches in front of the axle. In our case they were only three inches in front of it! There is no way to get the brake drum cables into these brackets without putting the cables in an extreme bind.

After taking a closer look at the axle placement and spring hanger brackets we found that this truck was originally a long bed truck! The previous owner must have cut the rear of the frame and moved the axle forward. We also discovered that the spring hangers were welded and bolted to the frame. One spring hanger was installed over an indent in the frame so there is a gap between the spring hanger bracket and the frame. This will make our work much harder when we do our planned suspension modifications.

With all of our issues mostly assessed, it was time to plan what was needed to make this truck a functional off-road truck that also provided comfortable, dependable transportation to and from the off-road areas. First, we need to address the axles, suspension, and steering. For axles we plan on installing some heavy duty one-ton axles from an older Chevy truck. To raise our truck and give a better ride we will do a simple 4” spring swap for now and in the future possibly add 52” springs in the front and 63” in the rear. For the front end we plan on adding a cross over steering system and possibly a hydraulic assist steering kit. The OEM steering is pretty much useless when the suspension is flexed to its limit especially with large tires. In this situation you can turn the steering wheel and find that the front wheels don’t move at all!

We also plan on replacing the rotted wood bed, installing all new window and door seals, reinstalling the air conditioning system, replacing the non-functional dash gauges with some Auto Meter gauges, and a set of custom built steps/rock sliders.
For the interior we plan on replacing the old bench seat with a newer seat, adding a dyno mat, new carpet, tilt steering, and improving the stereo system.

We have a lot of work ahead of us; so stay tuned as we build a more than capable off-road toy.