The Stovebolt Site Forums The Shop Area The HiPo Shop Adding a IFS to a 37 1/2 ton

Since I dont want to tear my 37 apart at this time I think I have found a bare frame,since it does not have a front axle will it cause problems installing a IFS since there is no way to find the centerline of the axle on the frame?. Does the manufactures of the suspensions have in their instructions reference points where to locate the crossmember?,I have never done this kind of modification before and need a few pointers. Jeff :confused:

When someone contacts me about installing a IFS on a truck year that I have not previously work on, I call up Heidts and have them send me the instructions so I will know all the work that is involved. You might want to give them a call.

I got mine from TCI for a 55 2nd series.All of the measurments were included in the instuctions. Dale

I just got my Heidt's crossmember in from the ups man and it has the measurments from a common hole in the frame for a measuring referance point . Looks to me you will be able to tackle this job without the cab on , have fun !

has anybody used the mid-70's Chevy truck IFS in an earlier model straight-axle truck? It appears it's a complete crossmember unit, springs, control arms, and all, which should bolt in with a little adapting. It's also got the front motor mounts on the same crossmember as the suspension. I'm considering swapping this unit into a 59 Carryall, along with a 70 Caddy variable-rate steering gear, mounted on a home-fabricated bracket ahead of the crossmember. Got any tips?
Jerry

I recently installed the fatman ifs and the measurement is from a hole in the frame to determine the axle centerline. It was a relatively easy installation.

Thanks!
This one's a long-term project, behind a whole bunch of race engines, about six custom rifles, and a construction project on a hotrod shop/gunshop on my farm! I've got enough projects under way to keep me busy for years after I retire!
Jerry

Hotrod,
There is at least one page out on the web that has instructions for narrowing the crossmember on that truck IFS. If I can find the link, I'll put it up here.

Thanks, I'd appreciate that!
The truck I'm planning to scavenge is a 3/4 ton with the 8-lug wheels. I've already got a Dana 60 8-lug rear end in the 59 Carryall, and I'm planning a Caddy 500/turbo 400 engine/transmission swap at some time in the distant future. When I do, I'd like the later model front suspension and disc brakes to be included. That would also put 8-lug wheels all the way around, and beefier front suspension. This one will probably do some trailer towing, and I like the idea of the better brakes and heavier running gear.
Jerry

Jeff, I put a stang II under the front of my 37 half ton and it works real good. The key is to find someone who has did this before and then save your self some big bucks. I welded a plate to the inside of my original frame and took it to a fellow that has put several front ends and clips under trucks and cars. I actually went to the junk yard myself and in the rain dropped all the stuff out from under a 78 mustang getting the rack and pinion (for a core) all for $75. I replaced all the bushings and ball joints paid the fellow for his work and had a NICE job including mounting tilt steering wheel for less than $800. With some of the kits you still end up buying more than the "kit" and I will bet it doesn't drive one bit better than my homemade job. Look around, make a plan. Measure twice and cut once!!!

Hotrod,
Here is the link to the article about narrowing a '73-'87 IFS crossmember: http://www.chevytrucks.org/tech/50ifsswap.htm

The last picture is the most telling - the wheels actually fit under the fenders.

Take another look...the caption under that picture reads
"(The photo above is with stock suspension--not IFS)"

Having just done this swap on a 3/4 ton truck, I can tell you *for sure* that if you see the wheels inside the fenders on a truck with one of these suspensions, it is *not* because the front end was narrowed 1-1/2", which is only 3/4" per side. It is because the right wheels were selected. Here's a shot of my truck, with front and rear ends from a '78 or so GMC 3/4 ton. All I have left to do is fabricate swaybar mounts.
[img]http://www.brakecylinder.com/images/52chevy/chev032.jpg[/img]

Those are late model (2001-2003) Dog** 3/4 ton steel wheels, which have almost 6" of backset. It takes all of it to compensate for the 7" wider track of the late suspension compared to the original straight axle. It would be nice if the wheels were another 3/4" under the fenders, but I don't think it would be worth the large amount of time and trouble it takes to do the narrowing.

Due to the taper in the '52 frame compared to the '78, I used 1" spacers between the frame and steering box/idler arm to maintain the original spacing and geometry. Since the spacers are so thick I was able to machine the back of the steering box spacer to receive the bumper bracket. (I'm kind of proud of this trick...I haven't seen a photo yet of another truck with this suspension that had the front bumper mounted.) If I were to narrow the frame, the spacer would be about 1/4" thick and mounting the bumper bracket would turn into a major project that would probably turn out marginal at best.

Joe

Joe Way Thanks for the links and yes they did work. Thanks also for the picture and additional information. What are *dog* wheels and do they come in 5 bolt that would fit my 1/2 ton 84 GMC front end?

Hey there, Weeds. As you know, we can't say "F O R D" on here without disguising it, and I've gotten into the habit of doing the same with other makers' names. The wheels are from D O D G E 3/4 ton, which have the same 8 bolt pattern as GM 3/4 ton.

I doubt that the half-ton D O D G E wheels have the same bolt pattern as half-ton Chevy. But--when I was looking for wheels, I noticed that late model--say in the 2000 and up range--GM trucks also had wheels with a lot of backset, and I suspect they do have the same bolt pattern. I used the D**** wheels because the center design will allow me to use original hubcaps, but if that is not a concern for you the late GM wheels, or one of many aftermarket wheels for late GM, might work well.

You need right at 6" of backset to get the tires under the fenders. If the late GM wheels don't have that much, or if the late 5 bolt pattern is different, or if you want to use original hubcaps, it will be time to talk to Stockton Wheel or another wheel specialist about building some wheels.

Joe

Joe Thanks for explaining to me about Dorfs and Dogs. Also the advice about wheels in general.Im going ahead with this IFS Swap because I like the heavy duty aspect. Saw one today at the Jefferson (Wi)car show and swap meet and it looked pretty good. I didn't get to talk to the owner but it looked like he had cut the 1 5/8 out of the middle and had big backset wheels. The wheels were actually about 1 inch inside of the fenders. The truck looked like it stood higher than stock. Can you direct me to Wayne Osbornes link? Thanks again for all the help.

Hmmm...I did say Wayne Osborne in that old message, but it's a different Wayne. Don't know his last name. His project writeup is at

http://www.itswhatsnext.com/ifs%20project.htm

here are a couple more links.

http://www.50chevy.freeservers.com/Bolt_on_Independent_2.html

http://home.att.net/~bobsplayce/trkifs.html

Hindsight is 20/20. I spent probably two hours figuring exactly where the IFS should be, fore and aft. Locating the suspension is complicated significantly by the fact that the ball joints move rearward as the suspension is loaded because the a-arms are at an angle, so you have to guess how far back the spindle will be at ride height. I think I did pretty well. See what you think.

[img]http://www.brakecylinder.com/images/52chevy/frontwheel.jpg[/img]

Note that the left lower a-arm was all the way to the rear of its travel where it clamps to the crossmember. I moved it forward about a half inch to about the center of its adjustment range, to match the right side. I expect that when I get it aligned, they will install shims so as to move the upper ball joint forward the same half inch, which will move the tire about 1/4" forward in the wheel well. When that happens, I think it will be as close to perfect as I could hope for. If I should decide it's still a tiny bit too far rearward, there's another 1/2" or so of adjustment left in the system.

Now...after the suspension was removed from the donor truck I made a cardboard template of the bolt holes in the donor frame so I could locate the steering box and idler arm. Here's the driver's side before I trimmed it to fit down onto the crossmember.

[img]http://www.brakecylinder.com/images/52chevy/template.jpg[/img]

After I drilled the holes in the '52 frame to match the crossmember I set the template in the space between the frame and the crossmember and stuck four bolts in through the template. I found that the forward hole for the steering box was exactly in line with the middle bumper bracket hole but about 3/16" high. I just pulled the template down 3/16", stuck a bolt through the template into the middle bracket hole and marked the other two steering box holes. (The top steering box hole is above the frame, and an angle clip must be fabricated to secure it.)

So...if ever I do this again, I will simply stick a bolt through the forward steering box hole in the template into the middle bumper bracket hole, and line the crossmember holes up with their template marks. Easy, huh?

Joe