Independent Front Suspension for Vintage Fords

First things first: Yank the sheetmetal. On a finished car, it is important to keep things lined up, so Bobby likes to stick a few pieces of masking tape on the body and the fenders as shown, then pen hash marks that can be utilized later to achieve proper panel alignment.

The front fender’s rear bolts on ’41-’48 Fords can be accessed from behind the kick panels in the interior and are often marred with rust. This particular car has already been restored once, so it came apart easily. Once the sheetmetal and radiator were removed, we found a bitchin’ traditional dropped axle frontend sitting there waiting for removal.

After removing the brake lines and shock mounts, Bobby picks up the car on a lift and removes the bolts in the Posies spring shackle. Once the front end is removed, the easiest way to move all that original steel around the shop is by bolting on the front wheels and rolling it.

After using a cherry picker to yank the mill, the next step in the process is to cut out the original crossmember. Before cutting anything on the frame, Bobby likes to weld a support brace made out of 1x1-inch box tube between the ’rails, which will keep things from bowing or moving. Next, use a torch to cut off the heads of four rivets on either side of the crossmember, then bang it out with a sledgehammer. Here you can see where the stock rivet holes are located on the frame.

Bobby stresses that one of the most vital steps in the installation process is ensuring proper frame alignment and position. If a new suspension setup is installed when the car is sitting at an unusual attitude, its ride height and handling characteristics will be marred. Make sure the car is sitting level (both front to back and left to right), measuring off the framerails for consistency.

All real rods need to sit at a rake, and Da Rod Shop uses 3 degrees as a good starting point. Using a Craftsman Protractor angle finder, raise the rear of the car up while it’s in the air until the desired measurement is obtained. Simulating the desired ride height before mocking up the new suspension ensures your car won’t have a Gasser-style nosebleed stance once everything is welded up and on the ground.

Use a grinder to clean off the 50-years-worth of road gunk and get a better look at the canvas for our unfolding project. The original ’rails on this ’47 are pretty clean, so the fitment process should be straightforward.

The factory bumpstops line up with the factory axle placement, so they are a good way to determine where the centerline of the wheel is on the frame. Screw in the stop and use a straightedge to draw a line up the side of the ’rail and over the top, which will serve as a reference point throughout the project.

Now lay a tape measure from the front of the framerail to the line you just marked on both sides of the car, making sure that the two measurements are identical. Repeat this step two or three times, as the ’rails could be bent or misaligned from an accident, which would have a negative effect on the car’s handling.

Lay a tape measure across the top of the crossmember as shown and find the center, then mark a line on both sides with a felt pen. This piece is 3-3/4 inches wide, so a line is marked at 1-7/8 inches. The mark will be used to align the member to the wheel centerline we just found on the ’rail.

Using a floor jack, raise the new crossmember into place, lining up the marks made in the last two steps. Measure from ’rail to ’rail to determine the center of the member; use the aforementioned protractor to ensure perfectly straight alignment (it should read 0 degrees when level).

Once everything is aligned and straight, the crossmember can be clamped into place prior to tack welding. Stock Ford ’rails have holes drilled on the inside to reduce weight and provide brake line access. TCI provides round patch plates in several sizes, which should be clamped and welded into place underneath the new crossmember. These plates increase strength and rigidity at the point where the new suspension will bolt on.

After welding in the patch plates and tack-welding the crossmember, remove the floor jack and check everything one more time for alignment.

TCI builds antidive geometry into its spring perch, which is why it is cut at an angle.

The tops of the shock and spring are mounted in the hat, so getting it lined up perfectly with the centerline of the wheel is vital. Using the same method demonstrated before, find and mark the center of the perch and line that up with the center of the crossmember.

As you can see here, the coil spring will not clear the stock frame, so the ’rail needs to be notched on both sides. While this sounds like a daunting task, it really isn’t bad if you utilize the template provided by TCI.

From the centerline of the member, the notch must be cut 3 inches wide (11/2 inches on either side of the line), 1/2 inch deep, and 3 inches down, essentially forming a cross-cut into the corner of the ’rail.

Using a ball-peen hammer or a pointed pick hammer, beat in the four pie-shaped wedges that have been cut into the ’rail until they meet in the center, forming a notch.

You can’t leave a bunch of cuts in the side of your framerail, so weld everything back together and then grind it all smooth, leaving a perfectly formed clearance divot for your new coil spring.

The spring hat must be lined up perfectly with the centerline of the wheel and crossmember; if not, the car’s alignment will be off, leading to driveability problems. Even if the pieces bolt together smoothly, that’s not a guarantee that proper positioning has been achieved. Bobby clamps everything into place for a trial fit, and then clamps a length of square tubing across the top of the perches to ensure level alignment.

Once the spring hat has been welded in, the lower control arm should be bolted up and checked for fit and alignment. Since Da Rod Shop has been doing so many IFS swaps lately, Bobby fabricated this cool tool to help move things along a little faster. By welding a length of threaded rod to a 4-inch piece of round tubing, the suspension can be mocked up without actually using a shock and spring to hold up the lower control arm.

The lower control arm should swing freely and line up with the bottom of the crossmember when bolted up to the spring perch. Check this first before bolting on the rest of the suspension parts.

The TCI spindle comes from the factory with the rotor and caliper already attached, so bolt the entire assembly to the lower control arm first. The upper arm bolts to the spindle first, then onto the spring hat.

Get everything mocked up with the threaded rod tool and place a magnetized level on the face of the rotor to make sure the rotors and wheel-mounting pads are positioned level and perpendicular to the ground. If everything looks good, the pieces should be taken off and painted, then reassembled with the spring (or airbag) going in first, before the upper control arm is installed on the spindle and hat.

Once everything is painted up nice and pretty and installed on the car, motor mounts are welded back onto the frame next to the new crossmember, and the engine is bolted back into place.

TCI supplies everything shown here for the conversion including nuts, washers, and a power rack-and-pinion unit. The rack is bolted up to the bottom of the frame and then attached to the front of both spindles. During the final assembly, make sure that all bushings are properly greased to prevent binding.

The deluxe Mustang II kit comes with a 1-inch sway bar that has aircraft-style rod ends and billet mounts. Using a sway bar is a good idea in any application, as it can reduce body roll in the corners and make for a better-driving car.

The sway bar bolts up underneath the car by mounting to aluminum blocks attached to the back of the crossmember and connecting to the lower control arms in front.

Ready to rumble! The fat ’47 is ready to get dressed back up in its sheetmetal, then it’s off to the alignment shop and back on the road. The lower control arms are pointing a little low now, but after a few weeks on the road when the springs settle, they should be pointing straight out. Keep in mind that whenever a new suspension setup is installed, it takes 50-100 miles for the springs and shocks to break in and for the car’s ride height to settle down a bit.

In the beginning, rodders only wanted two things from their steeds: speed and beauty. While heated leather seats, satellite navigation systems, and Tiptonic transmissions have yet to find their way onto the street rod scene, some modern Detroit-born technology has managed to cross over from the production line to the starting line, especially in the area of independent suspension.

Now don't get us wrong--adapting late-model IFS (independent front suspension) to early iron is certainly nothing new. In fact, street rods have been rolling on various versions of the easily adaptable Mustang II frontend since its inception in 1974. The difference between then and now--besides shaggy sideburns and polyester pants--is the fact that the street rod aftermarket has exploded with different kits offering Mustang II IFS for virtually every pre-war car ever built. Kit quality runs the gamut from super-sano hand-fabbed race-quality systems to direct take-offs from cars that actually rolled off an assembly line, and prices range accordingly.

We wanted to get a closer look at the installation process of a good, quality kit for a typical rod. After making a quick call to Bobby Castello of Da Rod Shop in Simi Valley, California, we found that Bobby and his crew were about install a Total Cost Involved (TCI) deluxe Mustang II suspension system (PN 206-2300-00) on a '47 Ford coupe. The car belongs to L.A.-area rodder Oran Zittella, who's been tooling around town in his '47 Ford for a few years now and desired a better ride than his dropped-axle frontend has been able to muster. Since power rack-and-pinion steering, disc brakes, adjustable spring rates, available drop spindles, and even optional airbags are all benefits of switching to IFS, the decision wasn't a difficult one. It turns out this is Da Rod Shop's third straight '46-'48 Ford IFS install, so things went quite smoothly. According to Bobby, the key to reaping the rewards of a Mustang II front end is in the setup and preparation, so follow along as we detail the nitty-gritty installation details.