Converting from 4-lug to 5-lug
Why convert to 5-lug?
Converting the front to 5-lug, what parts do I need?
Converting the rear to 5-lug, what parts do I need?
Foxbody drum to disc brake conversion
4-lug: converting to disc brakes, what parts do I need?
5-lug: converting to disc brakes, what parts do I need?
A note about master cylinders and brake boosters
The parking (e-brake) dilema
Another common and somewhat budget friendly option is to upgrade the caliper to a bigger one. The stock single-piston unit has a diameter of 60 mm. A direct bolt in replacement can be found from a 1991 Lincoln Mark VII. The Lincoln caliper has a bore diameter of 72.9 mm, so it should be able to provide some more clamping force. The larger caliper can also be found on these cars; 1986-91 Lincoln Mark VII 1986-91 Crown Victoria, 1984-86 SVO Mustang (4 cylinder turbo). You'll also need to upgrade the stock master cylinder (stock bore size: 21 mm) in order to run the larger calipers. A master cylinder from a 1993 Cobra or from 1994-98 Mustang V6 (all have bore size of 1-1/8") will work. All of these parts can be found in a scrap yard for dirt cheap.
73 mm calipers found on:
There are a few benefits gained from converting the stock Foxbody 4 lug setup to a 5 lug setup. First and foremost, there are many more wheel options to choose from, as the majority of manufacturers produce 5 lug designs (this is not to say there are no 4 lug choices... I am solely saying the 5 lug pool is larger). Furthermore (we'll get a little technical here), when switching the front over using parts from an SN95 donor, steering geometry is improved and thus is turn in, and the SN95 setup uses a sealed wheel bearing that is separated from the rotor. No more packing and repacking bearings if you need to take the rotor off. It also lays the foundation if you wish to go with an aftermarket or Cobra big brake upgrade kit (SSBC, Brembo, Baer, Wilwood etc.).
Switching the rear to 5 lug is all about upgrading the drums to discs. You can retain the drum brakes AND use 5 lug wheels, but as previously mentioned, the rear brakes aren't so great, so if you're gonna swap to 5 lug, it is advisable to spend a few extra dollars and convert the drums to discs (click here to skip 5 lug talk and jump straight to disc brake conversion).Converting the front to 5-lug
Converting the front to 5 lug is pretty simple. You can use the rotors from any of the following:
Converting the rear axle is not too difficult, either. First thing you will need is some axles found from:
Axles from 1994-98 Mustangs can work too, but they will increase the wheel track by 3/4" per side. Be careful when you choose what axles you want to go with, because although stock track and SN95 track axles both work to swap the Foxbody to 5-lug, you have to watch wheel spacing and fitment dependent on which track you've chosen to go with.
If you are going with a 5 lug disc brake setup, read the next section for more information about the disc brake conversion.
Converting the OE 4-lug rear drum into a 4-lug disc brake setup using the stock Mustang axles necessitates the use of rear calipers from any of the following cars:
Regarding caliper brackets, I do not believe any of the stock Ford sourced brackets will fit. Perhaps with some modification they can be made to work, but I am unsure. Alternatively, there is a ready-made version, by North Race Cars, that you can purchase and will bolt right up, no modification to any component necessary. (I think they are $150 for a set).5-lug: converting the rear to disc
If you want to go with a 5-lug disc brake setup, of course you first have to convert to 5-lug! After that, you can source nearly all of the parts from any 1994-98 Mustang (be it a GT, V6 or Cobra... any will do).
What you need from any 1994-98 Mustang: left & right calipers, caliper brackets and 10.5" solid rear rotors (5-lug, booyah baby!). I have heard that the stock SN95 (94-98) caliper brackets will work, with a little modification, simply by swapping right to left and left to right. The previously mentioned 'little modification' comes in the form of grinding down the inside of the bracket so that it doesn't grate against the bracket mount. Again, North Race Cars also sells a pre-made, direct fit bracket kit if you prefer a guaranteed fit. Alternatively, just grab the entire rear-end (8.8") and drop it in.Aftermarket Kits
Up until now we focused solely on a budget build, sourcing nearly all parts from other vehicles. The aftermarket does provide pre-packaged kits for both 5-lug conversion and disc brake conversion. If you would prefer to go this route, check online with your favorite vendors. Most offer their own conversion package featuring new parts. For example, American Muscle has a 4-lug to 5-lug conversion kit (made by Alloy USA - it retains the drum brakes) with all new parts for $400. If you don't feel like scrounging around your local scrap yard, it's a great option.
If you want to go seriously aftermarket (and spend a pretty penny or two), check the offerings from known brake vendors such as SSBC, Brembo, Wilwood and Baer. SSBC has a lot of really nice options for Mustangs of all years. They offer full conversion kits (drum to disc with everything included), big brake upgrades etc. They have nice stuff, and it is reasonably priced in my opinion.Some other useful information for BOTH 4-lug and 5-lug disc conversions
Some other parts you will need; adjustable proportioning valve and solid end cap, a new master cylinder (2 port, bore size dependent on caliper size) and some adapters to connect the caliper soft brake lines to the rigid lines. Generally speaking, a 1-1/8" master cylinder from a 93 Cobra or SN95 Mustang will be more than fine for the job.
Soft lines can be sourced from 1994-98 Mustangs, or be a handy-man and come up with your own adaptive solution. A note about the master cylinder, it is possible to convert a 3-port MC to a 2-port, so there is always that option too. As far as I know, it isn't too difficult, you just need some special adapters.
Furthermore, you may need to swap the stock brake booster out for another one if you change master cylinders. A booster from any SN95 V6 will work great.The dreaded parking brake (FIX)
Perhaps the biggest area of confusion regarding a disc brake swap (regardless of 4 or 5-lug) is how to get the parking brake to work. For this, you will need new e-brake cables. Specifically: (2) FMS M-2809-A cables, (1) FMS M-2810-A center e-brake cable. There is also a special modification that must be done at the parking brake handle for it to work correctly. In a nutshell, it requires eliminating the self-adjusting mechanism on the handle by cutting the tensioning spring and permanently attaching (via welding) the pawl onto the ratchet gear.
This guide was constructed to provide a general insight into what precisely is needed to complete a disc brake & 5-lug conversion on a Foxbody Mustang. Overall cost for any of the aforementioned conversions is highly subjective to where you source your parts. Junk yard A may charge more than scrap yard B. Perhaps Jack has a super deal on Craigslist whilst John is asking a little more. It is really quite hard to give a definitive price. Alas, no one wants to hear this, so I'll throw out some numbers.
|5-lug conversion (RETAIN drum brakes)||$200|
|4-lug rear disc conversion||$200|
|5-lug rear disc conversion (brake parts ONLY)||$300|
|Misc (fluid, adapters)||$30|
Any questions regarding specific parts or installation procedures, feel free to fire away in the Foxbody 5-lug/disc conversion thread.