How to Install a Front Subframe in a Vintage Mustang
01. The MTF subframe is considerably stronger than stock Mustang framerails, which are stamped steel. The MTF systems uses 11-gauge 2×3 tubing, making for a substantially stiffer frame for ultimate handling without the flex and slop of the stock suspension.
02. Here’s the front subframe assembly showing the MTF Independent Front Suspension installed, but obviously not on a car.
03. Measuring is the key to success. Get your Mustang up on stands or a hoist to let it rest evenly so you can make sure the front and the back are exactly the same height. One key tip is to always make sure you are measuring from the same point and same layer of metal. Measure the top of the frame rail at the back side of the core support on the inside and measure the front of the cowl to the radiator support and make notes of all the measurements you take.
04. Rich Smith shows where the spot welds are that need to be drilled out. Once that’s done, the factory front clip will come off.
05. Drill out the spot welds holding the stock framerails to the floorpan and separate the two. You might have to break out an air chisel or plasma cutter to make this easier.
06. Before you can begin welding things together, you must clean all areas.
07. From inside the car, you can see the holes from the factory spot welds. These will be used to temporarily screw the new subframe into place to hold it secure for welding
08. Prep the areas with weld-through primer. This allows welds to penetrate the metal and still provides corrosion resistance.
09. Your trusty floor jack will help you get the subframe assembly into place. After you slide it under the car, use the jack to elevate the front of the assembly to almost the same height as the engine panels, which will allow you to get the rear portions lifted into position and bolted to the front leaf spring eyes. Once the bolts are in, lift the front up into place, just to make sure the assembly clears and lines up with the engine panels.
10. Attach a small ratchet strap from the front end of the subframe assembly to the body of the car to draw the assembly tight to the car. Once you have it lined up where you want it, run some screws through the floorboard into the frame rails to hold it in place.
11. Start welding the subframe into place at the rear of the car, and then through the floorpan spot weld holes (after removing the screws of course). A standard MIG welder works just fine for this.
12. These engine compartment panels are a $349 option and can be used with any Mustang II-based suspension (they make them for their own suspension plus those from Heidts, Rod and Custom, and Total Cost Involved). They save a lot of time from having to make panels of your own after cutting the shock towers out of an early Mustang, and have the correct curve of the fender built in as well as come bead rolled for strength.
13. Mustangs to Fear used this spot welder to secure the engine compartment panels. You can use a regular MIG welder but if you’re not patient and go slow, you can warp some panels that will need to be metal-worked and maybe get a skim of filler to make show-car nice.
14. And it’s done—a 1967 Mustang fastback with Mustangs to Fear front subframe installed.
15. This is a finished and show-detailed customer’s car with the subframe installed so you can see just how nice it all can look with a few paint and body work tricks.