1963-1987 INDEPENDENT FRONT SUSPENSION UPGRADE

FOR 1947-1955 1ST. SERIES TRUCKS

By Steve Andereggen Jr.

The idea of using a 1963-87 independent front suspension first came to me shortly after my dad bought me my 1950 Chevrolet truck in 1991. 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. The 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. 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 yard to look and to see what just might work.

Again, I went back to the wrecking yard with a measuring tape in hand to see what the frame rail width is on a mid 70’s 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 for a few years as the truck was my main vehicle and needed it to commute back and fourth to college. Sometime in 1999, I became friends with a real nice guy who worked at a wrecking yard that I go too frequently to find out he has a 1949 GMC. We did some trading and I ended up with a 1963 1/2 ton front suspension unit. The suspension was set up with original manual steering components and drum brakes which I plan to change.

I ordered the disc brake conversion kit from Chevy Duty for my 1963 spindles and reused the mounting bracket that came with Chevy Duty’s 1947-54 Chevy truck power steering kit, witch I used with my original stock suspension, and relocated it up front on the frame rail as described later. I’m using a 1972 Saginaw power steering box off a Chevy 1/2 ton truck. This is what I originally had when I was using the with Chevy Duty 1947-54 Chevy truck power steering kit. Before you go any farther you will need to remove a few things from the frame. These include the front and rear spring hangers, shock mounts and brake line bracket (see drawing above). 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 (see photos below). This mark is my centering mark to mount the cross member.

At this point I decided to bolt the cross member directly to the frame instead of using the two 1” spacers. I figure this would help in my overall track width. The original track width of the front axle is 58 ½ inches from hub to hub. The 1963 IFS track width is 63 13/16 inches, about 5 ½ inches wider than the original. Most likely if you use this set up with or without the 1” spacers, you will have to use some type of reverse offset wheel to keep the tire in the wheel well.

MOUNTING THE CROSS MEMBER

I took the cross member to a local machine shop and had them take out around 1 5/8" (I don’t remember the exact measurement but this is what comes to mind.) out of the center with a plasma cutter. I waited as they did this and it took about 15-20 minutes for both cuts. I then drilled a bunch of holes near the new cuts on both halves of the crossmember. Next, one of the halves was plated on the inside using a plug weld method. Once completed, the other half was shoehorn over the plated half and then 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 using the 21 inch mark, you can mark and drill the mounting holes. I then bolted both halves to the frame rails and synched the halves together and plug welded the other half to the plates as before. Once both sides are welded in this manner, all of the welds were ground smooth. I then added 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-bolts that connects to the A-arm shaft assembly. When both holes on either side are drilled out, the cross member can be reinstalled.

MOUNTING THE STEERING BOX AND IDLER ARM

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 arm as these components are heavier duty than those used in manual steering trucks. 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. I don’t remember the exact measurement but it should be the same amount as was removed in the crossmember. Also, you will want to leave enough space for the center link to move in front of the cross member. I added about a 1/2" plate on either side of the frame to mount the steering box on one side and the idler arm on the other. NOTE: While taking some measurements for this updated article I found that there is 1 15/16” between the center of the steering box shaft and the frame on the drivers side. On the passengers side there is a 1 ½” between the idler arm bolt and the frame. I didn’t catch this but still works for me.

On the driver’s side, I mounted my power steering box near the very front on the frame. I reused a mounting plate from my earlier power steering set up and made another for a spacer on the side of the frame. The upper measurement is 3 ¼ inches and is made by starting from the front of the frame to the upper bolt hole in the spacer (see drawing above). The lower measurement is 4 ¾ inches and is measured the same as before but to the lower bolt hole. You will find rough templates for the power steering box mounting plates at the end of this article.

On the passenger’s side, the idler arm assembly is mounted to the frame so that the center link is parallel to the suspension cross member. The following measurements were made to mount the idler arm assembly. If you look at the front of the passenger side frame rail you will notice that the shackle mount is riveted in with
five rivets (see photo below).
Three horizontal rivets above the hole where the shackle mounts to and two along the bottom edge of the frame channel. I removed all castings from the frame leaving just the rivet holes and the larger shackle mounting hole. The idler arm assembly is mounted to the frame with two bolts. If you were to have the truck frame level, the idler arm mounts at around a 45 degree angle to the horizontal frame (see photo). If you measure from the upper mounting hole on the idler arm to the first rivet hole closest to the front you should have something like 11 ¾ inches. From the lower mounting hole on the idler arm to the same rivet hole should be 10 1/8 inches. From the top of the frame to the upper mounting hole is 1 ½ inches. NOTE: These measurements should get you close to where the idler arm needs to be. Again, I eyeballed everything when I installed this on my truck. I had no measurements to go from. These measurements are from my truck and work fine for what I did.

MORE TID BITS

Due to moving the steering box all the way up front on the frame rail, the driver side bumper bracket needs to be modified. The stock coil springs set the front end about 3-4" higher than stock height. To correct this you can get lowering springs, dropped spindles or a combination of the two. For my truck, I put air bags in. This gives the most flexibility to choose the height you want. I used the kit from Classic Performance Products along with their Air Ride compressor kit. This kit was very simple to install and gives me 9 inches of adjustable travel. You can see photos of this in the photo gallery at the end of this article. As for mounting the engine, I used the after market universal engine and transmission mounts. I hade these installed several years before when I still had the original axle. The 1963 IFS cross member, when installed, does not interfere at all with the universal engine crossmember. The original bell housing mounting cross member will have to be removed unless original 6 cylinder engine is used. See frame photos in the photo gallery for more details.