1963-1987 Indpendent Front Suspension Upgrade for 1947-1955 1st Series Trucks
This idea of using this type of suspension first came to me shortly after my dad bought me my 1950 Chevrolet truck ten years ago. After looking over my truck and making a list of what parts I will need or ideas of what parts I can use, I went to the wrecking ward to look and observe to see what just might work. Before I even saw the truck for the first time, I went out and purchased a book called How to restore your Chevrolet truck and read it cover to cover. This book is very helpful for the new-be like myself. That book is where I first pondered the idea of using this suspension. In the suspension section, the book shows a diagram of a 1962 torsion bar suspension. Looking at this picture I noticed that the cross member unbolts completely from the frame and is self contained in one unit. This is great I thought as I later learned that the 1963 through 1987? suspension system is identical except for the fact that coil springs are used instead of torsion bars. Time for some research.
Again I went back to the salvage yard with a measuring tape in hand to see what the frame rail width is on a mid 70s 1/2 ton truck is compared to my 1950 truck. The difference is about 2 inches. This is great because I could put a 1 inch plate on either side and call it good. At this point I just graduated High School and was struggling my way through college. I ended up putting this project on hold until about two years ago when my friend gave me a 1963 1/2 ton front suspension unit in trade for some electrical work, my specialty. The suspension was set up with original manual steering components and drum breaks.
I ordered the disc brake conversion kit from Chevy Duty and reused the mounting bracket that came with Chevy Duties power steering kit with stock suspension and relocated it up front on the frame rail. I will have to get the exact measurement when I get a chance Im using a 1972 Saginaw power steering pump off a Chevy 1/2 ton truck.
I then measured and marked the frame rail starting at the leading edge back 21 inches to where the forward upper A-arm bolt goes. This mark is my centering mark to mount the cross member. I then took the cross member to a local machine shop and had them take out an 1 5/8″ out of the center with a plasma cutter. I waited as they did this and took about 15-20 min for both cuts. I then drilled a bunch of holes near the new cuts on both cross member halves so that when I plate the inside of the cross member, I can weld through the holes that I drilled. Once one side is plated and all holes are ground smooth, I then shoehorn the plated half into the other half and installed the unit on the frame for fit. I have found that doing this step with the frame upside down is much easier than right side up. All the weight of the cross member is resting on the frame and not on jacks holding the cross member up. Once both halves are aligned on the frame rails I then mark and drill mounting holes. I then drilled and bolted both halves to the frame rails and synched both halves together and weld the other half to the plates as before. Once both sides are welded in this manner I then add some more plates to the outer surface for extra strength. If you do this right, it just might look like a factory job. Just a note. once you have welded the cross member back together as one piece, you will need to unbolt it from the frame rails and move it to the side so that holes can be drilled for the upper A-arm shim-bolt that connects to the A-arm shaft assembly. When both holes on either side are drilled out, the cross member can be reinstalled.
If you plan to use power steering as I did, you need to use 1969 or later power steering center link, tie rods, idler arm and pitman arms as these components are beefier than manual steering components. As for the steering linkage itself, I shortened the center link between both the pitman arm and idler arm so that each arm is parallel to the other. Also, you want to leave enough space for the center link to move in front of the cross member. I added about an 1/2″ plate on either side of the frame to mount the steering box on one side and the idler arm on the other. The steering box will be mounted all the way up front on the frame rail so the driver side bumper bracket needs to be modified. The stock coil springs set the front end about 3-4″ higher than stock height. You can get lowering springs, dropped spindles or as I did, put air bags in. I used the kit from Classic performance products along with their compressor kit. I have not yet added this yet but will let you know as soon as I get it installed. the same goes for a sway bar but that is to follow soon after the air bags.
(The photo above is with stock suspension–not IFS)