1979-1993 Mustangs have been known for their lackluster 4 lug brake and wheel design. Swapping and upgrading to a 5 lug option is one of the most common swaps for these awesome cars. Other than the 84-86 SVO and some of the other specialty models, all of these years came with the dreaded 4 lug setup. These brakes are much smaller overall and perform poorly compared to some of their upgraded counterparts. There are many different ways to upgrade your pony to the more updated 5 lug options and this article will go over all of them here including standard, SN-95, and aftermarket brands.
Many of you may ask, “Why should I upgrade to a 5 lug when my 4 lug set up is working just fine?” There are many different performance gains from converting your 79-93 Fox Body from 4 lug to 5 lug. The most dominating factor being the plethora of wheel options offered in a 5 lug over your standard 4 lug.
Depending on the options you go with, there can be added braking capabilities, less frequent maintenance, and heightened aesthetics of your Mustang’s appearance. Safety is also a key factor with your brake system; simply put, the better the brakes, the better the stopping power you have. This is also a key factor in high-performance cars. There is nothing worse than having a high horsepower Mustang and not being able to stop properly in it.
Budget can come into play on this as well and is something you will not want to ignore when choosing one of the many options to go with. The spectrum of the 5 lug swap can go from mild to wild and we will go over the options we offer here at LMR.com. We offer kits that start out around $400 all the way up to almost $3000 depending on the kit you want to go with. We make sure to take as much guesswork out of these equations so hunting for needed items is not needed.
Let’s start out with the standard or basic end of the 5 lug spectrum. 1987-1993 5.0L V8 applications are going to be the most common to get the swap. We are not saying that all of the other years and applications are impossible, but we will go over the differences here shortly. The most popular kit is going to be LRS-4234K. This kit will give you everything you need in one kit (other than the wheels) to have your Fox ready to roll. This kit features new front rotors, rear axles, brake drums, wheel bearings, wheels studs, grease seals, friction modifier, and gear oil.
One common question on these kits is will the existing brake shoes for the rear still work on my new 5 lug drums. The answer is yes. No modifications will be needed for these to work. Don’t worry 1979-86 Mustangs and 1987-93 2.3L Mustang owners, you can still run these kits, but some particular parts will have to be sourced from a donor car or a local salvage yard.
You will need to use 1987-93 5.0L spindles, struts, and calipers for the LRS-4234K kit to work. This kit includes 28 spline axles. We discuss more detail on axle splines in our 28 spline vs 31 spline axle article. If your car has a factory rear end, you will have 28 spline axles in the car already. However, if you are not the original owner and are unsure, pulling an axle is not too bad of a project and would ensure you are ordering the correct item.
We also offer the 31 spline version of this kit, LRS-4234B-K as well as slotted rotor versions of both, LRS-4234K-SLOT (28 spline) & LRS-4234B-SLOT (31 spline). If you want to go the 31 spline route, you will need to upgrade to a new differential unit like the Ford Performance 31 spline limited-slip differential, M4204F318C. All of the P/N’s listed in this section will have a full list of applicable wheels that will work with no interference issues. Other options will include the ones from our friends at SVE, Baer, and Wilwood. These will all work perfectly for a daily driven street car to mild track use.
These kits are honestly fairly basic to a certain degree. LMR will have many different ways you can upgrade these kits too. These upgrades would include high-performance pad sets like Hawk, EBC, and Stop Tech.
Brake line upgrades will also benefit you no matter what way you look at it. The factory rubber lines can swell under extreme pressures causing a drop in pedal pressure. Upgrading to a new set of braided stainless lines will dramatically improve your stopping capabilities. We off these as well from some of the best names in the business like J&M, Maximum Motorsports, and Russell.
LMR also has complete drum rebuild kits LRS-H7246K so you can ensure that the rear brakes are in correct working order. LMR carries all of your worn-out parts that may need to be replaced. These can include your factory booster and master cylinder. Proper operation of these will be a key factor in any braking system. These will work together to make sure the effort your foot makes on the pedal is transferred properly to the corresponding brake components. We also specialize in your “hard to find parts” like specific caliper hardware, brake line brackets, full chassis hard line kits, and all associated bearings for your Mustang’s brake system.
The SN95 style swap will be more diverse on wheel selection, brake upgrades, and overall driveline options for your Fox Body Mustang. SN95 brake swaps tend to be more expensive in most cases, but the upfront cost will offset the overall benefits and options you can go with in the long run.
Touching back on the 1986 owners that we had mentioned previously if you have this year, you have to source other particular items. Kits like the SVE-2300EK can kill two birds with one stone! This kit will include everything for all of the 79-93 spectrums for the 5 lug swaps. Featuring spindles, calipers, and rotors from 1994-1998 SN-95 Mustangs, you get high-quality parts at an economical price. You will still need to run an 87-93 5.0L strut for the 79-86 5.0 and all years for the 2.3L customers. It will even save money by keeping the rear drums!
We offer a great selection of OE style and upgraded versions of these struts as well. By doing this, you will not have to scour the junkyards or spend hours on end searching eBay or Craigslist. These will all work perfectly for a daily driven street car to mild track use as well.
All of the kits we have covered so far have retained the rear drums. If you are really planning on doing extensive track use or want the best overall stopping capabilities for your Fox, this next option is the way to go.
1994-04 Cobra-style upgrades are by far one of the best options for your Fox chassis. These kits upgrade you from front to rear with all of the highest quality components and performance your ride has been craving for. The 94-04 Cobra kits offered through LMR will include a 13” front rotor with a 2 piston caliper, these feature an 11.65” rotor and a single-piston caliper design just like the factory used. These kits are not for the faint of heart, many different “track only” cars like our 93 race fox use this same style braking system.
All of these style 5 lug swaps will come in many configurations. These will include the 28 and 31 spline axles, bare and painted calipers, and also standard rotors or upgraded slotted style. LMR and SVE have taken all of the guesswork out of these Cobra-style kits. We make sure to include all of the required parts for this to be a complete bolt-on application. We cover all of the major components like the parking brake cables, SN spindles with wheel bearings, axles, calipers with pads and brackets, all needed hard and soft lines, and even your fluid.
We have done extensive research and we make sure to cover all bases on these. We even make sure to include the proper Fox length axle sets that will retain the factory rear track width for your Fox. This installation process can seem daunting, but can easily be done by the average enthusiast in your driveway. These kits will be perfect for a daily driver as well as extensive track use.
When you upgrade to a 5 lug setup, you obviously have to get a set of 5 lug Mustang wheels. Luckily, LMR makes it easy with a variety of choices to choose from in different sizes, colors, and designs. The type of 5 lug kit that you choose to go with will determine the wheel selection that you can choose from.
For our basic Fox Body 5 lug swaps that use the Fox Spindle, you are going to want a 5 lug wheel that was designed specifically for Fox Bodies.
If you decide to swap over to an SN95 Fox Body 5 lug swap, the possibilities are quite endless. Most 1994-04 Mustang wheels that we offer will work. However, if you decide to go with Cobra brakes, you will need a wheel 17” in diameter or larger to clear the brake calipers. As with any wheel upgrade on a Fox Body, some clearance modifications may need to be done. For reference, you can check out our Fox Body wheel and tire guide. To get a new set of 5 lug wheels for your Fox, choose from our wide variety of wheels that fit Fox Bodies with an SN-95 5 lug swap.
LMR will also offer many of these options and parts as individual components as well. We fully understand that most builds do not happen overnight and if you need to piece anything together little bits at a time, we can always help you this way as well. Our staff and dedicated tech team can always help you out with any questions you have for your build.
Not all of these kits I have mentioned may be best suited for you, but remember we are always a phone call or an email away. Our staff is well versed in this subject as well as all of the 79-19 Mustangs!
As always check out our comprehensive articles, videos and website at LMR.com