1963-1987 INDEPENDENT FRONT SUSPENSION UPGRADE
FOR 1947-1955 1ST. SERIES TRUCKS
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 to 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 breaks 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 Dutys 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. Im 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 left). 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 CROSSMEMBER
I took the crossmember 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
As mentioned before I eyeballed were I thought the steering box and idler arm should be. This is where I made my big mistake. For those of you who have been following my instructions, I’m sorry. My entire steering geometry is wrong causing severe bump steer. Bump steer is when the wheel moves in and out as the suspension travels up and down. What I should have done was to make a template off the original frame in relation to the cross-member mounting holes and the steering box and idler arm holes. This would have made life much easier for me. I didn’t have an original frame to use as reference and that is why I eyeballed the linkage locations. This ended up being a very costly mistake on my part. By using a template for this you should have the same steering characteristics as the 1963-87 Chevy truck did.
The second thing you have to do is to make sure that the pitman arm and idler arm are parallel after they are mounted on the frame. It may be necessary to shorten the center link to make this work. 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.
MORE TID BITS
Due to moving the steering box all the way up front on the frame rail on the driver side the bumper bracket will need 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. I ran into another problem with this. In lowering the suspension, the overall track width increases due to the a-arms leveling out close to parallel to the ground. You can see photos of this in the photo gallery at the end of this article. As for mounting the engine, I used the aftermarket universal engine and transmission mounts. I had these installed several years before when I still had the original axle. The 1963 IFS crossmember, when installed, does not interfere at all with the universal engine crossmember. The original bell housing mounting crossmember will have to be removed unless original 6-cylinder engine is used. See frame photos in the photo gallery for more details.
One of the most asked questions I get is why I narrowed the frame. I don’t like spacers. Plus, narrowing the frame takes off an inch or so off each side in overall track width. I have a set of 1990’s S-10 wheels that I like and wanted to use on this truck. The wheels are 15 X 7’s with a 4 inch back spacing. In other words these tires are wide compared to the originals. The 1963-87 suspension is much wider that the original 1947-55 1st series is. I narrowed the crossmember in hopes to narrow the overall track width just enough to get the wheels and tires within the fenders. This didn’t happen. What this did is to cause my tires to stick outside of the wheel well just over an inch on either side. This wasn’t the look I was going for. So, how am I going to reduce track width even more?
I had two choices. Change out all my wheels and go with custom offsets and widths or try to find someone to build custom rotors. Either one would most likely work. I still want to keep the S-10 wheel as I am using 8 of them, my truck with side mount spare tire and matching utility trailer with side mount spare tire. As for the custom rotors I’m guessing they would be very expensive and I couldn’t find anyone that does that sort of thing. I know this is done for other applications and have even asked around at SEMA the 2 years I attended.
In the end I ended up selling this project as it was getting to expensive for me and I wasn’t very satisfied with the results I got for what I was looking for. Don’t get me wrong. This suspension set up does work. I’ve seen several trucks with this suspension, with spacers, and they look great. I personally was
not happy with my results. Should you have any questions feel free to call or e-mail me. I will try to answer all questions. Again, I never finished my suspension install and ended up selling it. Currently there are no commercially made aftermarket IFS out that will give stock height. Most all aftermarket IFS will drop your ride height 3-4 inches right off. I didn’t want that.
GM METRIC G BODY/S-10 SUSPENSION
As for the last comment, I just found a guy that has built a crossmember to fit the 1947-55 1st series trucks and uses GM metric G body/S-10 suspension components. The track width is within a half inch of the stock width and the ride height is an inch less of original. The person who designed this is Scott Danforth. Here is some info he has passed on to me in his email. You can also find this info on the stovebolt.com forum. Here is the link to the forum. This is what you get.
The cross member includes boxing plates for the frame that go from the current front radiator cross member back to the transmission cross member. The IFS crossmember takes about 3 hours of cutting and welding after you have the stock front suspension out of it.
Donor cars can be any GM Metric (78-87 G-body, 82-04 S-series) The G-bodied cars have M12 bolts in both lower A-arm bushings, while the S-10 changed from M12 early to both M12 and M14 later. My instructions cover this.
97 and later S series Blazer/Jimmy/Bravada have dual piston front brakes. The whole spindle assembly is needed; however these add major stopping power for about $300 on eBay (from s-10 Warehouse)
Aftermarket A-arms are available for those that want to run tubular a-arms. If you get A-arms from Global West, let them know that you need the ones off the good jig. Apparently one of their jigs is bad and they have sent bad parts out (their story to one of my customers – covered on the stovebolt forum). A-arms are cheaper for the G-bodied cars than the S-10 Trucks for the same parts.
Speedway motors has 2″ drop spindle available for $105 for the spindles only and $150 for spindles and 3″ lowering blocks for the back (assuming 2″ wide springs on an S-10)
Price is at $525 currently with $10 extra for simple brackets for using a 4th generation F-body rack and pinion. Other racks that are rumored to fit are Ford Explorer and Dodge Durango/Dakota. The Mustang 2 stuff from Flamming River will also work, however looks a little light.
The price is similar to the Mustang 2 weld in prices. From time to time I run a special for stovebolt members. I have these made 5 at a time and currently have one kit in stock, however I think the boxing plates that I have in stock are the early revision. If that is the case, I would reduce the overall price by $30. They work, just require a bit more weld time on the bottom because there is a 5″ long gap that needs to be welded (you can see the larger weld bead in a few of the photos). The new revision fits much better (measure twice, cut once I miss measured the bottom of the frame). When that goes, it takes 3 weeks for my fabricator in Green Bay to make another 5.
I ship UPS and can ship freight collect to a UPS account. Shipping to a commercial address is less than shipping to a residential address. I use UPS.com for obtaining prices and is pretty close to what I actually pay (sometimes more, sometimes less) I don’t make money on shipping.
I would like to thank all those who have called me over the years asking questions about this conversion. I just recently stumbled across a forum and found that this conversion is referred to as the Andereggen/Joyce IFS conversion. I couldn’t believe it. I have spoke to others who have done this conversion and will try to get some photos of their vehicles with contact info posted here. I will also try to get my photos in the gallery larger so that you can see detail.