Mark Houlahan
Tech Editor, Mustang Monthly
September 15, 2017

A great thing has been happening over the last decade. There’s been a huge push to actually get out and drive our classic Mustangs. We certainly appreciate the concours restorations and those that are caretakers for the specialties of the breed like Boss 302s, Cobra Jet Drag Pak Mach 1s, and other such dream rides. However, the majority of the Mustangs still on the road today from 1965-1968 are drivers and cruisers that see weekend fun at a cars and coffees or a their town’s monthly cruise-in. These cars are the ones that are seen by Joe and Jane Average and often light their fires to have a classic Mustang of their own. So any time you can get behind the wheel and be seen is an opportunity to help grow our hobby and keep classic Mustang ownership and interest alive and well.

To that end, many people have been looking for ways to make their classic Mustang more comfortable and safer to drive. We’ve covered many of these updates and fixes over the years, including three-point seatbelts, tilt steering columns, adding air conditioning, and more. One such upgrade we’ve touched on in the past has been lowering the seat platforms to gain headroom for tall drivers. This used to mean removing the platforms, cutting them down, and welding them back together—laborious process. However, we can thank National Parts Depot for making the process a whole lot easier with its new 1-inch lower seat platforms. These heavy-gauge stamped platforms are ready to weld in, lowering the mounting platform for your seats by 1 inch. You can increase legroom even further by incorporating NPD’s seat-track extenders (PN61704-1E) while reinstalling your seats. Installation requires interior removal and the cutting and drilling of the original platform’s spot welds, but saves you the time of having to salvage, cut, and re-weld the stock platforms to gain that inch of headroom some of you so desperately need to drive comfortably and safely.

Our friend Brian Stilwell, an Orlando, Florida, firefighter is just one such person who could use a little more headroom. At 6 feet 1 inches, he felt he could use a slightly lower seating position, despite using a one-piece headliner. His 1965 hardtop (longtime readers might remember his foray into inline-six performance upgrades a few years back) is in the middle of fresh paint and some fiberglass body upgrades. So the interior was already out of his hardtop, making it the perfect candidate to see just how these new platforms install and fit.

1. While Brian’s hardtop already had the interior out, it was not really all that difficult to get to the seat platforms. Remove the front seats, then remove the doorsill plates, kick panels, console (if equipped) and pull the front half of the carpet out of the car. You can just fold back the rear half. Remove any insulation, and clean the lip of the seat platform with a wire wheel, so you can identify the factory spot welds.

2. Once the lip of the platform has been cleaned to bare metal, the spot welds become readily visible. Use a center punch to mark the centers of each weld so you can drill them out. We’re starting with the passenger side on his 1965 hardtop.

3. A spring-loaded spot weld cutter is your friend here. They’re not the cheapest tool, but they are the tool for the job and will make your life so much easier. Using the spot weld cutter, cut through the spot welds one at a time to free the seat platform from the main floorpan.

4. Once all of the spot welds are found and drilled out, use a small pry bar to help remove any spot welds that are hanging on after being drilled through. It shouldn’t take much effort to free the platform. If it’s really working against, you double-check that you haven’t missed a spot weld or two.

5. Inspect the floorpan for rust or any other damage, and repair as necessary before continuing. Thankfully, Brian’s floorpan was in excellent shape with just light surface rust. So we cleaned it with a large wire wheel. Once clean, apply a coating of weld-through primer.

6. Spray weld-through primer on the new seat platform around its perimeter where the welding will occur.

7. To be able to weld the new platform into place using the plug-welding technique and the typical 110-volt MIG welder, you must make a series of holes around the perimeter of the new platform. A drill and properly sized bit work just fine, but a pneumatic hole punch do an even quicker job. Either way, space your holes about 1 inch apart.

8. Place the new low-profile seat platform in the car, locating the seat mounting bolt access holes in the floorpan and aligning the platform with these openings. Mark the location of the platform with a Sharpie just in case it gets bumped while you prep for welding.

9. Give the seat platform a few tack welds, ensuring it maintains the correct position. If needed, work any of the platform’s edges with a hammer for a better fit. Finally, plug-weld all of the platform’s drilled or punched holes, moving around to prevent heat warpage.

10. The completed installation will look just like the original, just lower. Grind any welds down that need it, and you’re ready to tackle the driver’s side in the same manner.

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11. Once we pulled the driver’s side factory seat platform free, we placed in on our work surface to compare it to the new NPD low-profile version. The measuring tape doesn’t lie. The stock platform sits at 4 inches, at its highest point, and the platform measures in at 3 inches in the same spot. Every inch counts when you’re north of 6 feet tall!


NPD’s Low-Profile Seat Fitting Tip

NPD Low-Profile Seat Platforms fit 1965-1968 Mustang hardtop and fastback body and floors only. It is recommended to fit 1969-1970 model year carpeting when installing these, as stock 1965-1968 carpeting will sit higher than the seat platform, causing poor fit and appearance.

Left seat platform: PN 010673-200A, $69.95
Right seat platform: PN 010672-200A, $69.95