converting manual drum brakes to factory power front disc

AcesArneson said:

Mustang Steve sells a conversion kit if you're interested. I bought one but have not installed it yet. You'll need minimum 18" wheels to fit the 2015-2019 GT brakes on your 65-73
https://mustangsteve.com/product/s550-brakes-on-65-73-mustang/

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This would defeat the purpose of having bought the complete stock set up from Jeff, (DropTop73),

I changed my 72 Coupe from factory front drum brakes to factory front disc brakes and used original parts from parts cars I parted out. My set up is all original and I had to change out the interior brake pedal support bracket that the four studs from the power brake booster attaches too. I was able to use factory brake lines from these parts cars as well as the disc brake proportion valve. I like the better stopping power I receive from the front disc brakes.

Stanglover said:

Well, this could end up with the "snowball effect".
Back when I did a booster add-on, I also went the whole hog and added bearings to the clutch pivot from Mustang Steve (Scott Drake make a set as well). This really smoothed the clutch operation. I went a step further and added oil-lite bronze bushings to replace the plastic bushing in all the linkages. Doable for sure, but a lot of work and totally worth it imo.
As for the booster, here are a couple of pics of the opening after I drilled out the old studs. Of course, I removed the entire hanger bracket. On the brake pedal, Mustang Steve supplied a replacement pin that I welded in 2" down from the manual pin. see pic. I think a pin can be bought that either screws in or has a nut and lock washer on the back.
I went with SSBC 4 piston brakes and actually ran these for years before adding a booster and to be honest, I didn't notice much difference. I do use an adjustable valve for the rear drum brakes, so they are totally separate from the front.
Did Jeff supply disc brake spindles? Maybe I missed that bit.

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Can you still drill out the old studs if you aren't going to remove the hanger bracket? Our conversion kit calls for a new 2" hole that will allow a pin to be attached for the correct connection to the booster. So we will leave the hanger bracket and reinstall the same manual brake pedal once we have attached the new pin. (I think). We aren't completely sure on anything but just want to confirm we can drill out the studs.

I should also note that our conversion kit calls for us to drill out four new holes for the brake booster to be installed. (This is a factory manual front/rear drum brake car) Should we do it this way instead? If that is the case then should we leave the two bottom studs that are there now? Any help/recommendations would be great!

hendrixftw22 said:

Can you still drill out the old studs if you aren't going to remove the hanger bracket? Our conversion kit calls for a new 2" hole that will allow a pin to be attached for the correct connection to the booster. So we will leave the hanger bracket and reinstall the same manual brake pedal once we have attached the new pin. (I think). We aren't completely sure on anything but just want to confirm we can drill out the studs.

I should also note that our conversion kit calls for us to drill out four new holes for the brake booster to be installed. (This is a factory manual front/rear drum brake car) Should we do it this way instead? If that is the case then should we leave the two bottom studs that are there now? Any help/recommendations would be great!

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Well, I did this swap back in 2010 when I installed the SSBC disc kit which uses the original drum spindles. I did not do the booster upgrade till 2016 when I had to have the engine out (again) for a rebuild, so still a long time ago to remember exactly, but I'll do my best to answer your questions.

Because the engine was out, I had all the access I needed to work on the bracket, which I mention in some detail in my original post.
As best as I can remember, the studs are just through the firewall and if I remember, I cut the studs off then drilled them out. I would need to go back and study my pictures to jog the old memory cells!!
The reason they want you to drill a bigger hole is the position of the push rod pin is lower than a non booster manual brake. There was a cover plate over the bottom half. You can see where the original m/c fitted.
Here are a few pics that might help explain. Green arrow, m/c nuts, blue arrow, cover plate, red arrow, bracket studs to be removed.
I don't recall any other mods to the bracket which of course, was out of the car.
Hope that helps.

Edit; drill 4 new holes?? that might depend on the booster you bought. On my car, I first bought a smaller diam. booster kit that would not work with shock tower braces, so I bought a Cardone reman original booster which fits the original hole pattern.