Wheels-Tires Need Some Help - Brakes Upgrade/Wheel fitment

86HO5.0 · Dec 13, 2025

SN95 Control arms will improve tire clearance, turning radius, handling and slightly improve bumpsteer.

245-255 tire width is about the max front tire size you can run on an 86, why not improve front geometry? The narrow K member with the SN95 spindles has caused issues on a couple different cars where obtaining acceptable camber wasn't possible (with CC Plates). This issue is why I ran SN arms instead of fox arms. Gained A LOT of tire clearance up front with the same size tire.

I edited a post above--DO NOT run 96-04 spindles on a Fox. Adding spacers will only make it worse.

AeroCoupe · Dec 13, 2025

Good info on the SN95 lowers with the narrower k-member. There were some guys that had the Fox lowers and running 17x9's with 275's but I haven't seen them in years as I haven't gone to a race in about 15 years.

I do not understand your comment on spacers? Are you referring to the rack limiters or the 0.330" stack of washers or spacer required when running Fox ball joints with an SN95 spindle?

Running 96-04 spindles may not be as optimal as the 94/95 but I ran them for a couple of years in my Coupe with a stock k-member and had zero issues. You just need to run a bump steer kit and before anyone starts talking about having to set the bump steer with a gauge and all that stuff you do not have to for a street driven car. Most just make sure that the tie rod ends are parallel with the lower control arm at ride height and that works really well. Both my cars have the 96-04 spindles with the bump steer set up this way and one is a full Maximum Motorsports suspension and the other a Griggs Racing suspension.

Even with the 94/95 spindles you can get into bump steer issues if the car is lowered very much.

I will also say that everyone wants waaaay too much for the 94/95 spindles when you can get a set of the 96-04 online for around $60 a set and a tapered or though bolt bump steer kit from MM is $200 so about the same price as the 94/95 spindles or a little less. If you plan on running a tubular k-member you need to find out what spindle they designed it around which is why I went with the 96+ spindles as the MM and Griggs k-members are designed around the 96+ geometry.

86HO5.0 · Dec 13, 2025

I was referring to spacers with a bump steer kit, they will make the geometry worse.

Good point on future K-Member plans. 94-95 spindles are $$ these days, got lucky when I bought mine. Picked up spindles w/good hubs and a nice SN95 rack for $150.

FWIW--The bolt hole spread on the FRPP proportioning valve is the same as the stock proportioning valve. I deleted the stock valve entirely and put the adjustable in the factory location on the DS frame rail.

jaygee15 · Dec 13, 2025

In regards to the K member, I will need to replace mine from what I understand since my car is a 6 cyl and will be swapping to most likely a 351 windsor(slim but possible chance to a coyote gen 1). How does this effect the recommended suspension/brake upgrades given thus far?

86HO5.0 · Dec 13, 2025

If an aftermarket K-member is planned for the future, decide which one you plan on using and buy the parts to support that. Some aftermarket k-members are designed for 96-04 spindles and will have that in the product description. As far as I know most aftermarket members mimic the 87-93 width. In this case it would probably be a good idea to utilize the Fox LCA's, proper camber shouldn't be an issue and the added width of the SN95 arms may end up being too wide, especially if using the wider 96-04 spindles.

Brake upgrades wouldn't be affected by what K-member you choose.

Willybill32 · Dec 13, 2025

86HO5.0 said:
SN95 Control arms will improve tire clearance, turning radius, handling and slightly improve bumpsteer.

245-255 tire width is about the max front tire size you can run on an 86, why not improve front geometry? The narrow K member with the SN95 spindles has caused issues on a couple different cars where obtaining acceptable camber wasn't possible (with CC Plates). This issue is why I ran SN arms instead of fox arms. Gained A LOT of tire clearance up front with the same size tire.

I edited a post above--DO NOT run 96-04 spindles on a Fox. Adding spacers will only make it worse.

I’m curious about the SN-95 lower control arms. I have an ‘86 5.0 with 17X8 front wheels, and I’m getting the driver’s side tire rubbing when I hit a bump. Would the SN-95 control arms help with that?

Bill

86HO5.0 · Dec 13, 2025

Depends on your current setup and wheel offset.

My complete front setup; Stock 86 K-member, SN95 LCA's, 94-95 spindles, 94-98 Cobra spec brakes, Tokico Fox struts with MM CC plates, Tokico lowering springs (about 1" drop), and 05 GT 17x8 Wheels (45mm offset) with 245/45-17 Continental summer tires. MM Fox swaybar, 1 1/8" o.d. SN95 rack with stock SN95 limiters. I can turn full lock to lock with zero rubbing. Zero rubbing on bumps. Could easily clear 255/40-17's, 255/45's would be tight but would likely clear.

Willybill32 · Dec 13, 2025

86HO5.0 said:
Depends on your current setup and wheel offset.

My complete front setup; Stock 86 K-member, SN95 LCA's, 94-95 spindles, 94-98 Cobra spec brakes, Tokico Fox struts with MM CC plates, Tokico lowering springs (about 1" drop), and 05 GT 17x8 Wheels (45mm offset) with 245/45-17 Continental summer tires. MM Fox swaybar, 1 1/8" o.d. SN95 rack with stock SN95 limiters. I can turn full lock to lock with zero rubbing. Zero rubbing on bumps. Could easily clear 255/40-17's, 255/45's would be tight but would likely clear.

I have Bilstein struts, ‘87-‘93 spindles, rotors and calipers, FRPP “B” springs, stock K-member and steering rack and the LMR 17” pony wheels. It all worked well until the engine, suspension and K-member came out for engine bay paint. MM caster/camber plates added during reassembly. Since reassembly and alignment, I get rubbing, but only on the driver’s side. I’ve had it at a good shop and they think I should replace the front springs, but they have little mileage on them. I’m booked into a local suspension shop, but they can’t take it ‘til late February!

86HO5.0 · Dec 13, 2025

With your current setup, SN95 arms would make things worse unless you change wheels.

Based on what you're describing, the issue didn't exist until the R&R of the K-member? Verify the K member is centered correctly in the chassis before making any other changes. Rubbing on 1 side suggests to me the front track is off center.

Does the car lean? What's the ground to fender height on each side?

Willybill32 · Dec 13, 2025

86HO5.0 said:
With your current setup, SN95 arms would make things worse unless you change wheels.

Based on what you're describing, the issue didn't exist until the R&R of the K-member? Verify the K member is centered correctly in the chassis before making any other changes. Rubbing on 1 side suggests to me the front track is off center.

Does the car lean? What's the ground to fender height on each side?

Yes, the problem arose after the body shop work. The driver’s side floor to fender opening is about 3/8” less than the passenger’s side, but the driver’s side tire sits in 1/8”-1/4” more than the passenger’s side. I’m wondering if a coil spring spacer would help…

Bill

86HO5.0 · Dec 13, 2025

Don't install a spring spacer. The K member wasn't installed correctly, get this resolved before making any other changes.

EDIT--Do you have a printout of what the alignment was set at?

Willybill32 · Dec 13, 2025

86HO5.0 said:
Don't install a spring spacer. The K member wasn't installed correctly, get this resolved before making any other changes.

EDIT--Do you have a printout of what the alignment was set at?

No, but they said they used MM’s guidelines for alignment for street use.

Thanks for your help. I’ll just wait ’til I get it into the other shop in late February.

Bill

AeroCoupe · Dec 14, 2025

As far as I know you do not need to replace the stock k-member due to the car being a V6. It was the older cars that had the inline 6 cylinder that the k-member had to be swapped out to go to a V8.

I will say that if you are planning on a 351W a tubular k-member makes things easier but not absolutely necessary. For me I would not swap a Coyote in without one but I would not do a Coyote vs a 351W on a naturally aspirated setup. You can put a really nice stroked 351W in the car for about the same money and have way more power. Boosted is a whole other story as I would go with a Gen 2 Coyote.

jaygee15 · Dec 14, 2025

AeroCoupe said:
As far as I know you do not need to replace the stock k-member due to the car being a V6. It was the older cars that had the inline 6 cylinder that the k-member had to be swapped out to go to a V8.

I will say that if you are planning on a 351W a tubular k-member makes things easier but not absolutely necessary. For me I would not swap a Coyote in without one but I would not do a Coyote vs a 351W on a naturally aspirated setup. You can put a really nice stroked 351W in the car for about the same money and have way more power. Boosted is a whole other story as I would go with a Gen 2 Coyote.

Coyote or Godzilla are on the list, but probably out of realistic reach due to complexity of swap and cost. Most likely will be a 351w, 408 stroker, or maybe even a 347stroker from blueprint. I do want to reserve the possibility of adding turbo down the road to whichever I go with. But budget, ease of install, will most likely take precedence.

jaygee15 · Dec 15, 2025

Someone mentioned in another group, that the 93 cobra brake booster may be too large if I am going with a windsor motor?

AeroCoupe · Dec 15, 2025

Nope. Have a 95 booster (same physical size) in the T-Bird and zero issues.

jaygee15 · Dec 15, 2025

so this is the stuff I need for right now to get my brakes going and use my existing calipers and rear brake setup.

Mustang Brake Proportioning Valve Plug M-2450-A - LMR

Plug your factory proportioning valve with this 5.0 Resto direct fit Mustang Rear Disc Conversion Proportioning Valve Plug!

lmr.com

https://lmr.com/item/LRS-2140H/1994-95-Mustang-Gt-V6-Brake-Master-Cylinder?utm_source=google&utm_medium=cpc&gad_source=1&gad_campaignid=20122150528&gbraid=0AAAAAD62FUyNTyZroK0JjuRUjX8oeP6LB&gclid=Cj0KCQiAgP_JBhD-ARIsANpEMxwI7y55mZRMLw9QC9tfED2WSSZ1eTLH5qa3dGn0xtYjBfqv0pVQlUMaAlVyEALw_wcB

https://lmr.com/item/LRS-2005C/1993-Mustang-Cobra-Power-Brake-Booster?utm_source=google&utm_medium=cpc&gad_source=1&gad_campaignid=21804152373&gbraid=0AAAAAD62FUxrKIluOtR4_Ikqpx54jHQZY&gclid=Cj0KCQiAgP_JBhD-ARIsANpEMxygbVPSOjjVfGxSbtSvjheExxYW6TUUsGB86oj5rPZtEtkJwhuX02EaAnY9EALw_wcB

https://lmr.com/item/M2328C/Mustang-Ford-Racing-Adjustable-Brake-Proportioning-Valve?utm_source=google&utm_medium=cpc&gad_source=1&gad_campaignid=20122150522&gclid=EAIaIQobChMI34Wr47C2kQMVTl1_AB20LTNgEAQYASABEgI8VvD_BwE

Master Cylinder Installation Kit, 1993 Cobra/1994-95 GT m/c in 1980-86 Mustang

and is this what you are saying I need to do to the stock proportioning valve?

https://www.youtube.com/results?search_query=fox+body+manual+proportioning+valve

AeroCoupe · Dec 15, 2025

You need to get the 1993 Cobra MC as it has the preferred 1” piston. As far as what you need to do to the combination valve is gut just the proportion valve. Do not mess with the rear of the combination valve as that is the shuttle valve. So in this video do what he does with the front which is the proportioning valve:

View: https://youtube.com/shorts/KguyVoQZuNo?si=srgaBVzRe7EMvwmc

Here is why you leave the shuttle valve alone:

https://www.corral.net/posts/14886034/

jaygee15 · Dec 16, 2025

What is the best budget setup for K member. I see some come with no spring perches, some like the BMR with premium perches, and some setup for coil over. I am planning to go with traditional spring/shock setup to keep this budget friendly. Do the ones without perches use the stock? What would be best for my setup and desired use of car as basically just a street car weekend cruiser that I will have some back street fun with here and there etc.

AeroCoupe · Dec 16, 2025

You need spring perches for coil springs so BMR or UPR. Probably some other ones.

DOM Steel Tubular K-Member w/Spring Perches SBF (fits 79-95 Mustang) U

UPR's all new Mild Steel K-member saves weight while adding maximum header and oil pan clearance. Designed for the abuse of hardcore drag race, road race, and Street Enthusiasts.

www.uprproducts.com

I have zero experience with them so do some research and look for reviews.

Wheels-Tires Need Some Help - Brakes Upgrade/Wheel fitment

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lube between the nut and the face. I know my lubes

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But at least it's tight!

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But at least it's tight!

Active Member

But at least it's tight!

Active Member

But at least it's tight!

lube between the nut and the face. I know my lubes

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Member

lube between the nut and the face. I know my lubes

Member

lube between the nut and the face. I know my lubes

Member

lube between the nut and the face. I know my lubes

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