What a wonderful chronology of your project! We have two 1973 Mustangs, a low mileage 40+ year barn stored true survivor 1973 Mustang Convertible & a deeply restored 1973 Mach 1. The vert needed very little work, as it was in nearly perfect condition. That did not stop me from doing a few upgrades. With the Mach 1 it was a little different story.
At first the Mach 1 it looked like it was in really good condition after we inspected & purchased it. Photos are attached. I knew it had some
minor rust at the bottom rear of the driver door, on the hood, & on the rear taillight panel. I figured to get it in good shape it would take less than $10k at most. Hearkening back to the lyrics of a 60s song, "Laugh, laugh” (
https://genius.com/The-beau-brummels-laugh-laugh-lyrics). The song has nothing to do with cars or Mustangs, but the lyrics seem appropriate.
In our progress photos, placed into a YouTube video, you can see what began as a minor project soon became a major project. There was a lot of underlying corrosion, deep inside the various seams, that only became evident as we dug ever deeper into our one little minor project, & removed trim pieces. In a short time we shot from an expected $10k or less project to well over $100k. Once we began to see the extent of underlying damage, & had a realistic sense of what it would take to restore the Mach 1, we went forward with our eyes wide open.Many folks would have patched it up, sold it to some high school kid who would end up destroying it anyway, & just found a different Mustang. But, because of a commitment we made to the seller to do right by "his baby," & for “love of the breed," we opted to have the Mach 1 restored properly. It is surprising how good the undercarriage looks. There is no rust on the underside. As for the metal body panels & other related parts we needed to replace, we kept as much original metal as we could, which meant a lot of labor time with re-sectioning new metal to old metal that was still in good condition - instead of replacing entire body panels.
Instead of using plastic filler (Bondo) for various seams, the tech was very experienced in using lead, like Ford used back in the "old days" with the original builds from the factory on these Mustangs. Leading is more costly than using plastic filler, but we felt the result would make it worth the while. Some metal panels & parts were at the time not available new, so the body tech ended up doing some fabrication for a few of the parts, also very costly - but well worth it. Every week we stopped to check on the progress, & take photos, for 13 1/2 very long months. & every month we paid about $10,000 to help the shop offset the ever increasing costs being incurred - as opposed to expecting them to fund the project .
After seeing your notes every few photos, I decided to alter the series of photos in our one YouTube video, & embed a spoken narration on the project. I am not certain how long that will take, or when it will be done. But, in the meanwhile the progress photos for our 73 Mach 1 are in the following YouTube link:
I also posted a YouTube video of the finished project. That link is provided further down in this post.
As for specs, here is what the Mach 1 has.
The prior owner replaced the original 2.79:1 rear axle with a 3.5:1 TractionLok unit. The original 302 2v engine had a problem with the distributor shaft & oil pump, so he replaced it with a 1994 F-150 351W (not C). He had the 351W built to a moderate street/strip level of performance, 360 HP at the crankshaft. Included in the building of the 351 he installed Hooker ceramic coated long tube headers, Edelbrock RPM Performer intake manifold, 750 CFM vacuum secondary Holley carb, forged aluminum pistons with
only 9.5:1 compression so it could handle the 89-90 octane non-ethanol gasoline out in our area (Rochester, NY), a 3/4 hydraulic cam, hardened valve seats, MSD ignition system & distributor, & a fully open air filter housing.
We also replaced the idiot-light instrument panel with a Dakota VHX analog gauge instrument panel. The Dakota instrument panel was a great move, as I could now see the actual oil pressure, tachometer, & engine coolant temp, along with some other goodies offered with the VHX unit. The VHX temp gauge also alerted me to a problem I had not been aware of with the idiot-light dash. At low speeds or prolonged idling the temp moved from 200 to 260 degrees. With the idiot light never illuminating at that higher temp I was unaware of what was going on. But, it made sense. When the prior owner moved from the 302 to a 351 engine he installed a larger radiator. But, he used the old fan shroud, which was too small to properly direct air over the cooling fins. The fix could have been easy, but I did not want to simply find a properly sized fan shroud.
I have long been interested in converting a mechanical cooling fan system to an electric fan system. This was my opportunity. I ended up getting a Champion three row aluminum radiator with a matching shroud that held dual electric fans. Rather than use the simple single stage coolant temp switch to turn the fans on & off via a fan relay, I used a variable temp thermostat to control the fan relay. I later added an amber LED light that illuminates when the fans received power. I can see the amber LED light under the rear section under the hood when sitting in the driver's seat.
In addition to the electric fans I added a Garmin Drive 72 GPS, to include optional wireless cameras. One camera is used as a backup display, the other is used for a front bumper clearance. I can have up to 4 wireless cameras, but those two do the trick just fine.
I also added a WebCam. The center mini-console was adequate, but I wanted a full length console. I got one from ACP. In the console I replaced the ash tray with a fabricated Power Panel. In the Power Panel I have two 12v outlets, used to power the GPS & WebCam, a dual port USB outlet, & a digital voltmeter.
The taillights were less bright than I wanted, so I installed a set of LED taillights with sequential flashing. The sequential turn signals require a switched 12 volt power source, & the backup camera also needed 12 volts for the camera. The video signal from the camera is sent wirelessly to the GPS display, so I was spared the need to run an A/V cable. For the 12v switched power I ran a wire from the fuse block into the trunk.
With the addition of the GPS. cameras, WebCam, LED panels, & Power Panel in the center console, I found the demand on the electrical system was about 42 amps with everything turned on & running. The alternator was a side terminal design, but originally could only put out 42 amps. I had the alternator rebuilt using a larger rotor winding part. The output now is 70+amps.
After the restoration I decided to go to the next step. The C4 tranny began to slip on 1-2 upshifts at Wide Open Throttle, so I purchased a performance built AOD to replace the C4. I also wanted to keep the original floor shifter, & used a Lokar adjustable shift rod from Summit Racing. I have the entire AOD swap video posted on YouTube, to include how to adjust the Throttle Valve Pressure & providing a list of vendors/parts used in the video descriptions.
The AOD replacing the C4 was a wonderful move. Now at 60 MPH the engine is running at about 1,850 RPM as opposed to 2,850 RPM. The Mach 1 is more pleasant to drive & is still nimble & spirited at lower speeds.
I was after was not a TransAm look like you were. I was more after a Street Machine look. The Mach 1 already had a front spoiler, I added a rear wing, rear louver slats, & a set of Dzus hood locks. The color was originally Saddle Bronze Metallic. The prior owner repainted the car in Valspar Sunset metallic. We went to PPG Sunset Orange, a fine grain metallic, translucent paint shot over a base white paint to give it a candy effect visually. We also used PPG Hot Rod Black Matte for the blackout schema on the hood, the spoilers, & the louver slat assembly. Each coat of base white, color, & clear was blocked & wet sanded before any subsequent coats were shot. It was a very long & costly processes, but the results speaks for itself. This is truly a magnificently & truly perfect paint job, following meticulous prepping, masking, blocking, & wet sanding. Anywhere we go the Mach 1 commands attention, & has the plenty of performance to back up its incredibly gruff, edgy look. Here is a YouTube walk-around of the Mach 1 at the end of its last day or restoration:
Below are the YouTube videos of the AOD swap, to include the Throttle Valve Pressure setting, & how I spliced the AOD Neutral sAfety/Backup Light switch wires into the old C4 NSS/BUL switch harness:
The following link is for the Neutral Safety/Backup Light Switch splicing:
https://youtu.be/yHWY903N4bs
https://youtu.be/XZ7CkcY1vFQ
https://youtu.be/vdR-z3KV0UE
https://youtu.be/YCBBgd-olQ0
https://youtu.be/NcYr68atRjM
https://youtu.be/iFNXTGXNNcQ
https://youtu.be/2tTwnbcZZkY
https://youtu.be/8QncIKQTvNo
https://youtu.be/b4lnPReGWuM
https://youtu.be/zfYe--Gsjdk
Setting up Throttle Valve Pressure from the carburetor cabling, & how the original auto tranny floor shifter behaves with the AOD when shifting manually:
https://youtu.be/KYIAqqYUKNo
This video below shows there is a difference between TV pressures in Neutral vs Park for an AOD:
https://youtu.be/6hZJEnGCPvY