Restoring 83 5.0 GT help on improved brakes

83gtresto

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Oct 25, 2020
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I located and bought back an 83 5.0 GT that I bought new. It is pretty gone in some ways. The front bumper cover is gone and the panel that holds the headlights is missing. The rear bumper cover is pretty bad too. I have been looking for replacements for a few days but haven't had much luck, any help here would be appreciated.

The other thing is the brakes, they are stock. Back when it was newer I jokingly called them Pinto brakes because they were about the same size as the old ford pinto. I read something about later model brake parts retrofitting. I would like to get rid of the 4 lug wheels. it's the only V8 car I ever had with 4 lug wheels.

I have a fabrication shop and have been thinking about making a one off fiberglass front bumper cover replica, but that is a lot of work. Does anyone know of a source for 83 front bumper covers, also does anyone know of a good brake upgrade that gives serious stopping power without buying aftermarket parts.
 
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General karthief

wonder how much it would cost to ship you a pair
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Mustang5L5

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You can go a few ways here.

You can go with an 87-93 setup, but with 5-lug rotors and rear drums, you can go with an 94-04 4-wheel disk brake setup. You can do GT brakes, Cobra brakes, or aftermarket Big Boy Brakes. Really all depends on your budget and appetite on scouring for some use parts mixed in with some new parts.
 

KRUISR

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I agree with Mustang5L5 ... lots of combinations you can go with. All depends on how big you want the brakes, what are your fabrication skills like and 4 or 5 lug.

I have an odd ball set up, Lincoln LS rotors, calipers and pads, re-drilled for 4 lug. 11.8" front rotors, 11.33" vented rear rotors. I have spindles from an '01 with fabricated adapter brackets to fit stock caliper bracket to spindle because of larger rotor. I need to use 16" wheels or larger with this setup.

If you want big 4 lug set up I can point you in the direction of some bigger rotors to re-drill and get 12.83" front, 12.83" rear with the same Lincoln LS caliper and pad. All OEM rotors from various manufacturers.

When I go 5 lug I am either going to go with 11.8" 05-14 Mustang vented rears or as big as 12.44" Freestar rears using same Lincoln LS calipers and a new adapter bracket.

For fronts I haven't decided if I will go with a 12.44" Mustang, 12.8" Taurus or 13.22" Mustang, again with the Lincoln LS calipers I already have and new adapter brackets.

If you want REALLY big OEM brakes in 5 lug, go with Police Interceptor Sedan brakes, 13.85" fronts and 13.58" rears. Calipers are only slightly bigger pistons than Mustangs. Then fabricate the adapter bracket you need to fit your choice of spindle.

What are your thoughts or plans for the type of set up you want?
 

83gtresto

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Thanks for the reply. I want to get rid of the 4 lug setup. I am retired and I have a machine shop, so I can fab most anything. I was looking mostly for factory type parts to keep the cost down, and I really like big brakes. The plans are a 5.0 with a single turbo. When you said police interceptor rotors, are you talking about crown vic police rotors. I have been looking at the Cadillac Brembo front caliper. I do have the stock 83 front spindles, I have to figure out if I need to swap those and what it takes. Mostly I can find a group of parts that have been made to fit by others so I can avoid buying a lot of parts that don't go good together. One twist it I bought a new Ford Motorsport 3.73 posi rear axle in the 1980's the type where you bolt in/on your stock axles and brakes. I don't know if that rear end limits the types of brakes that will work.
 

90sickfox

Wasn't a pretty sight...and I've got big hands
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Sounds like a c clip eliminator rear axle set up.

First, you'll want an aftermarket or 86+ k member. The 83 control arm mounting points are narrower.

Second, you want to grab some 94- 95 front spindles. ( if you are going to us a maximum motorsports k member they recommend 96 - 04 spindles )

Third, you'll need to redo the entire brake system...new booster, master, adjustable proportioning valve, brake hoses ( braided hoses tend to fit almost all calipers due to design at the caliper side ).

This can be done in many different ways. Depends on your pocket. All of the newer mustangs have better brakes than the 83.

What spline axles do you have ? If 28 spline you could use 90 Ranger pick up axles...the drivers side is used for driver and passenger side axles in a mustang. If 31 spline you'll have to buy stock length aftermarket 5 lug axles. Since plans to go turbo I'd go the aftermarket route anyways. There are many options for rear discs with c clip eliminator or regular rear axles.

ATS calipers almost bolt on 94 - 04 spindles...only needing offset bushings to work. I haven't done it but have watched the threads closely.
 

eighty5fox

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If you want big brakes on a budget go with the ATS brembos with 94-04 cobra 13inch rotor. I chose to drill out my spindle but other people have made new threaded sleeves. If you have a machine shop that would all be a no brainer for you.
 

KRUISR

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When you said police interceptor rotors, are you talking about crown vic police rotors.
No I meant Taurus police interceptor. 2013-2018 have huge brakes. You WILL need 18" rims though. Front rotors are 1.26" thick, rears are about .78".

Will definitely require changes to total brake system.

If this is a route you were going to go, here is how I would build the system:

- Keep your cross-member and modify according to Mathis Performance Handbook 2 for your year range.
- Get 96-04 spindles with hubs
- Front control arms - your choice. Can re-bush OEM units or get an aftermarket unit. I would recommend Fox length as opposed to SN95 length. I tried SN95 arms and was not able to get a 245 tire to fit right in fender (1990 style) - arms pushed the tire out too far, rims were 0 or +8mm offset.
- Offset rack bushings set to move rack down. This in combination with the above mods does not require a bump steer kit for outer tie rod (this is my current set up).
- If you can find a Taurus Police Interceptor at salvage yard take the rotors (if good still), calipers, caliper mount bracket, pads, flex hose and chassis mount along with 3-6" of hard brake line. Both sides, front and rear. To mock up... install spindles with struts, put rotor on held snug with lug nut and position caliper on rotor aligned to spindle mount points. Now fab a bracket to connect the two. Keeping Taurus flex hose and chassis mount if they fit the space will save trying to adapt lines. The short piece of hard brake line you took is for the threaded fitting to connect into the chassis mount, just need to re-flair brake line with Taurus fitting (this way you know it works, it just came apart from each other). Repeat for all four corners. You have just installed really big 5 lug OEM brakes on your mustang.
- Booster should be SN95 (I think 94-95 fits best, but others can be modified to fit).
- For master cylinder you will want a 1-1/16" bore unit. The Taurus Police Interceptor uses a 1-1/8" bore. I think the 1-1/16" is the closest we can get for the mustang. I believe 96-04 cars with dual piston fronts may have these MC's (I am not 100% confident this statement is correct, but either way you want the 1-1/16" bore unit). I personally went with a MC and proportioning valve from an '01 V6 that was a non-ABS car. I used this prop-valve because non-ABS cars run the brake lines to the rear the same as the Fox cars do... 1 common brake line, split at differential housing to each wheel. Also because '01 V6 cars use dual piston calipers in the front so the front/rear bias should be correct with no need for an aftermarket prop valve. To fit this to my Fox I just needed to re-flair my brake lines at the prop valve with the SN95 fittings.


So what should it cost in parts. Here will be the used part prices: (prices are from a pick-a-part yard I have used in the past - in the US). Prices in USD
Rotor x4 = $15x4 = $60
Caliper, bracket, hose x4 = $25x4 = $100
Pads x8 = $2x8 = $16
Booster, MC, Prop valve = $50
Spindle with hub x2 = $38x2 = $76

So $302 for a big brake kit (13.85" front, 13.58" rear) using OEM parts.

Same parts all sourced from Rockauto:
Rotors = (Raybestos Performance - $40 each rears, $60 each front) = $200
Caliper, bracket, hose = $450 without cores to return, $260 with cores (Raybestos remanufactured)
Pads = $56 (Raybestos Performance)
Booster = $100 (94-04 mustang)
MC =$100 (1-1/16" mustang MC)
Hub x2 = $25x2 = $50

Would still need spindles and prop valve, but total of rest = $956 without caliper cores, $766 with cores.

Both scenarios require some simple fabrication of mount bracket adapters (grinder, welder, drills).

What was not included in pricing is any control arm changes, offset rack bushings, axles, rear gear changes and wheels as 18" wheels will be required.

Many may not like my thoughts on a big brake system and that's okay. This is how I would do it (and may do it in the future).
 

Mustang5L5

i'm familiar with penetration
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I get the sense the OP is rather new in terms of Mustang brake systems, so why overcomplicate things? Just stick to a basic SN95 front/rear disk brake package that's been done. No need to reinvent the wheel and require him to start fabricating brackets and mounts for a setup. Sn95 brake setups are all over the place, and a 100% bolt on.
 
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KRUISR

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Mustang5L5 ... I agree the basic SN95 front/rear set up is much more effective than the stock Fox brakes.

My detailed description is really not much more work than the basic swap. Simply fabricating the adapter brackets (which I did anyway when building my Lincoln LS brakes swap) and re-flairing the brake lines.

The detail was also to give others ideas that Cobra 13" rotors are not the only way to get bigger brakes and we don't have to be limited to just those options. Using ATS calipers is another example of going outside the box with alternative ideas. Isn't that how this hobby got started. Trying to improve the cars with what is easily and cheaply available.
 

83gtresto

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The rear axle I bought new and installed was the 8.8 Ford Motorsport 3.73 made to bolt in and use the stock 83 axles and brakes. Does anyone have any input on caliper mounting brackets for the rear.
 

GUSS327

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I agree with Mustang5L5 ... lots of combinations you can go with. All depends on how big you want the brakes, what are your fabrication skills like and 4 or 5 lug.

I have an odd ball set up, Lincoln LS rotors, calipers and pads, re-drilled for 4 lug. 11.8" front rotors, 11.33" vented rear rotors. I have spindles from an '01 with fabricated adapter brackets to fit stock caliper bracket to spindle because of larger rotor. I need to use 16" wheels or larger with this setup.

If you want big 4 lug set up I can point you in the direction of some bigger rotors to re-drill and get 12.83" front, 12.83" rear with the same Lincoln LS caliper and pad. All OEM rotors from various manufacturers.

When I go 5 lug I am either going to go with 11.8" 05-14 Mustang vented rears or as big as 12.44" Freestar rears using same Lincoln LS calipers and a new adapter bracket.

For fronts I haven't decided if I will go with a 12.44" Mustang, 12.8" Taurus or 13.22" Mustang, again with the Lincoln LS calipers I already have and new adapter brackets.

If you want REALLY big OEM brakes in 5 lug, go with Police Interceptor Sedan brakes, 13.85" fronts and 13.58" rears. Calipers are only slightly bigger pistons than Mustangs. Then fabricate the adapter bracket you need to fit your choice of spindle.

What are your thoughts or plans for the type of set up you want?
HEY I just seen a realy interesting one on youtube look up POOR MAN MODS Its a red supra that was using the 93 cobra setup but for 300 went to 4 piston mercedes calipers with huge 350 z rotors and 86 toyota e86 brake lines CHEAP and big ass brakes
 

KRUISR

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Cheaper but not quite as big as Police Interceptor sizes above, but bigger than Cobra set up...

Freestar rear rotors (12.44")
2011 Mustang GT front rotors (13.23")
Lincoln LS calipers, caliper brackets and pads - all 4 corners. Caliper brackets have same bolt spacing on the mounting side as Mustangs.

What is nice is these are all OEM parts from vehicles that are readily available (makes them cheaper).

Just need to fab bracket to locate caliper in correct position (not as hard as it sounds),
 

Mustang5L5

i'm familiar with penetration
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Should really do a brake balance calculation with custom brake setups. You want to try and achieve 70/30 split on our mustangs as best we can. Too much up front or in the back can actually hurt brake performance. The factory OE setups are pretty close to the desired split, so any deviation should be calculated out.
 

KRUISR

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If using all Lincoln LS calipers, piston area works out to 65/35 split, almost the same as 93 Cobra. Slightly smaller piston sizes all around though for the Lincoln set up.

Lincoln LS (65/35 split)
Front
45mm/38mm pistons - 5450 mm2 total area (both calipers)
Rear
43mm piston - 2904 mm2 total area

93 Cobra (64/36 split)
Front
60mm single piston- 5650 mm2 total area
Rear
45mm piston - 3180 mm2 total area

Stock front rotor on Lincoln is 1.18" thick and rear is vented at 0.79" so can accommodate the thicker '14 Mustang GT brakes (13.23"/11.8") which are about same thickness. Front and rear are both thicker than '03 Cobra's front and rear.
 

GUSS327

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Aug 5, 2020
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Cheaper but not quite as big as Police Interceptor sizes above, but bigger than Cobra set up...

Freestar rear rotors (12.44")
2011 Mustang GT front rotors (13.23")
Lincoln LS calipers, caliper brackets and pads - all 4 corners. Caliper brackets have same bolt spacing on the mounting side as Mustangs.

What is nice is these are all OEM parts from vehicles that are readily available (makes them cheaper).

Just need to fab bracket to locate caliper in correct position (not as hard as it sounds),
YES I did see the police rotors . I'm really looking to stay 4 lug but want better brakes . I went with the stock rotors still good with EBC STREET PADS for now in rear all new drums and pads from drums Dynamic Friction and Centric fleet brake shoes all new hardwear .
 

Mustang5L5

i'm familiar with penetration
Mod Dude
Feb 18, 2001
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If using all Lincoln LS calipers, piston area works out to 65/35 split, almost the same as 93 Cobra. Slightly smaller piston sizes all around though for the Lincoln set up.

Lincoln LS (65/35 split)
Front
45mm/38mm pistons - 5450 mm2 total area (both calipers)
Rear
43mm piston - 2904 mm2 total area

93 Cobra (64/36 split)
Front
60mm single piston- 5650 mm2 total area
Rear
45mm piston - 3180 mm2 total area

Stock front rotor on Lincoln is 1.18" thick and rear is vented at 0.79" so can accommodate the thicker '14 Mustang GT brakes (13.23"/11.8") which are about same thickness. Front and rear are both thicker than '03 Cobra's front and rear.

Brake rotor diameter is part of the calculation. It’s not just piston surface area. 93 cobra would be closer to 66/34.

here’s an example of the inputs needed by way of an online calculator


I didn’t run the numbers however for your setup. I was more or less speaking to tossing huge 4-piston calipers up front with puny rear brakes. I think I calculated out almost an 80/20 brake bias when using the ATS 4-piston brembos and SN95 GT rear 10.5” disks. In that case, the setup was not an upgrade since the rear brakes were not doing much at all. It is possible to have too much front brake.
 
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KRUISR

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Used the calculator. Lincoln LS setup I am running (11.8"/11.33" rotors) came in at 66/34

Same calipers with 2014 GT rotors (13.23"/11.8") came in at 70/30.

Changing rear rotors to Freestar 12.44" rotors (still 13.23" fronts) came in at 68/32.

Still Lincoln calipers with Cobra rotors (13"/11.65") came in at 70/30.

Neat tool.
 
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