David Stribling
April 7, 2019

One of the great advantages of the popularity of the Mustang is the fact that complete subassemblies are now available for major structural repairs. But how do we do it in our home garage and come away with something that tracks down the road straight? We’re here to show you the process.

The patient for our demo install was in a major incident on a highway—an overzealous troll pulled in front of this 1967 hardtop and proceeded to slam on the brakes. Using proper defensive driving techniques, the owner slammed on the Wilwoods and made some evasive moves, which resulted in saving the others around him but taking off the front end and right quarter of the Mustang. Normally with damage this severe in sunny SoCal you would just go get another car, but this one has been in the family since new, so it is time for some major work.

In the past, we would go cut an entire clip from another car in the yard, but those sources are all but dried up. Enter Dynacorn International. While the quarter-panel of the car was replaced with an N.O.S. part found online, the front end is being replaced with Dynacorn’s Apron assemblies (PN 3630R and PN 3630S), radiator support (PN 3640F), strut rod brackets (PN 3640FAWT and PN 3640FBWT), and firewall to floor supports (PN 3631ZEWT).

Preparation Is Key
Whether you plan on doing this by yourself or with a little help, do all your homework before trying to weld parts in place. Since this car was in an accident and was severely bent, we chose to have the remaining body checked out by a local frame shop. The dimensions for your Mustang can be found in the body section of your Ford factory shop manuals. We had a copy of the dimensions from a body shop manual, but you might luck out and find them online.

If you are doing this in your garage, note that garage floors are not level by design. They generally slope to get rid of water. You either need to level your car or square up the body with the floor angles in mind. Safety is always a concern, so make sure you have plenty of safety stands before proceeding. A cheap leveling system can be made from a set of scissor-type jacks from the local salvage yard—you can use them to correct for variations in the floor. Always use safety stands with the scissor jacks. One place on the body that is parallel to the floor is the rocker panels—take your measurements from the four corners of the outer rocker panels to assist in leveling the body. If you cannot level the body, you may need to have the car straightened before you weld new panels in place.

If possible, photograph everything before you start taking things apart. Items like the strut braces sometimes don’t go back in the same place. Take additional measurements to add to the factory drawings. Remember, cars that are rusted, wrecked, or have endured 50-plus years of road use are usually not in the same position they were when they left the factory. If you have some friends’ cars that are available, take some measurements off of those cars too. There is some variance on how Ford put these together, and you don’t want to use just one example because it may have suffered from one of the above issues.

Finally, while we didn’t get the chance to do this, do one panel or section at a time. Don’t just start hacking off all the parts. A rusted part may still be a good guide for installing the replacement part, and once you take off more than one panel you lose that reference point.

Aftermarket Parts
A quick note about aftermarket parts: Your car went through 50-plus years of torture, and the aftermarket parts are good but may not be perfect—you may experience some holes not lining up. News flash: some of the holes on the factory panels didn’t line up either. I once took a part that wouldn’t fit one car, and then I took it over to another car—it fit worse. Sometimes it is the car as well as the part. Be patient.

Export Braces
Shelby-style braces are obviously much stronger and less flexible than the originals (and have less adjustment). Some of the aftermarket braces are not very good quality, so make sure you have a good one. Always use your export or shock tower braces to help center the shock tower assemblies.

Tram and Measuring
Pro shops have some really nice gauges to measure the squareness of the body. You can make one yourself out of some conduit and threaded rod that will do the job. Make sure you are measuring from the same point on your gauge. For example, choose the side of the hole edge rather than trying to measure from the center. Make sure you mirror your measurement to the other side. If you need to, you can use some string and a weight (a nut works great) to create a vertical line to check side measurement from the holes listed on the Ford drawing. If the car is elevated enough, you can mark the string at the Ford distance and then check these marks with your level.

Strut Rod Braces
The strut rod braces serve two purposes—they provide the mounting point for the strut rod bushings, and they provide rigidity to the front end by bracing the side rail and radiator support. Once these go in, they really lock the front down. If you need to make any small tweaks to the front end or rails, do it before these go in. The dimensions for these are not on the factory dimension chart, and I have seen them mounted with a lot of variance. Mark where your originals were mounted prior to removing them or use several examples to find the location from other cars. The front suspension pieces can be mounted and squared to help locate these pieces as well.

Assembly
Once all your preparation is done, the assembly usually goes quickly. You will need plenty of body clamps, Cleco pins, and straps to hold it all together until it is welded in place. After the first few tack welds are in place, double-check (and continue to double-check) your measurements. We added a set of Tin Man Fabrication subframe connectors to our hardtop, and they fit the squared-up chassis perfectly. For a job like this, it is possible to do it yourself—just remember that preparation is 75 percent of the job and patience is necessary.

Although this is an extreme situation, there are times when complete front framerail assemblies are a better choice than repairing individual panels. When the framerail is completely rusted out, sometimes it is easier to replace the whole assembly rather than to cut out the bad parts.
Dynacorn sells complete front rails and aprons already preassembled. The complete front end can be replaced using the company’s radiator support, framerail extensions, and strut rod mounts.
The first thing you need to acquire: the correct frame dimensions for your car. The body shop manual for your year has these dimension (1969 shown here), and they are available aftermarket—you might even find them online.
Preparation is king. With the old metal removed, we found a buckle on the passenger-side firewall, so we straightened it and re-measured before we began installing the front end. Note that in 1967 there was no passenger-side torque box on a hardtop—only on the driver side.
Doing this on your garage floor, you want to make sure the car is level before beginning. Since most garage floors are not level, one way you can level your car is to get four of these screw-type jacks from the salvage yard. They will allow you much more adjustment than just jackstands alone. Always use safety stands along with the adjustable jacks.
The outer rockers are the one place that you can measure for a level car. Take a measurement in all four rail corners with an angle gauge.
Professional body shops have these tram gauges for measuring the straightness and how true the frame is. You can make yourself one (shown on the bottom) using a piece of conduit, a couple of couplers that will slide on the conduit, and a couple of pieces of threaded rod with a ground point. The cost is less than $10.
Part of our preparation was to square the body and install the N.O.S. quarter-panel on the passenger side along with a new Dynacorn taillight panel (PN 3643E). Unibodies get their strength from the welded panels, so this will help keep the body from flexing.
Preparation for the installation takes longer than the actual installation of the panels. Here a strap was used along with clamps and Clecos to get the panels in place. Extra safety jacks will also help.
Master fabricator Randy Domeck begins by checking the diagonal square of the front end by a point on the cowl to the front opposite side of the front aprons. Note that he has installed the export brace that the owner will be using when the car is completed.
A quick note about the export brace: In this scenario, we have a wrecked car, aftermarket frame assemblies, and an aftermarket export brace—something is not going to line up perfectly! The original shock tower braces were much more forgiving than the export brace, so you may have to “influence” something to make it all fit.
Although we did make sure all was level, our install at the top and bottom apron mounts were perfectly flush to the firewall. Always a good sign.
Squared and welded on. The new frame extensions went in right over the existing spots from the originals.
Double-check all measurements. The lower control arm points are 19⅛ inches wide center to center and we’re right on the money.
About the strut rod mount location: I have seen them hanging over like this one, and I have seen them flush with the edge of the framerail and everywhere in between. The dimension for this piece isn’t on the Ford dimension drawing for 1967.
Here Randy is making sure the front is square to the corner and even on both sides. You can do some minor tweaking of the front before the strut rod mounts are installed; once they are on it isn’t moving.
We have other cars to take dimensions from (use an average of several cars, not just one other example), and one other thing you can do is install the front suspension components, making sure that the strut rod runs parallel to the bracket and the rubber mounts are in the middle of the adjustment on the threads.
The framerail extensions were right on the money—so much so that we were able to install these Tin Man Fabrication subframe connectors (PN 109401) that install in the end of the framerails. They slid in perfectly.
Our 1967 hardtop is now ready for weld finishing and some sheetmetal fitting. Take your time and prepare, and you too can do this in your own garage.
You can use some monofilament line and some weights hung from the points noted in the dimensions, and then let Isaac Newton help you level up the rails. Note that cotton string stretches, so if you use it double-check your measurements.

Photography by David Stribling