98 to 79 Brakes

Sep 2, 2017
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I own a 79 Mustang Pace Car and I have a 98 GT for parts [Engine driveline donor] Can I use the braking system/rear axle from the 98 to my 79. And yes I have read several of the brake swap post on here. Thx Dave
 
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Mustang5L5

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Yes, you can.

The rear axle will be 0.75" wider each side due to the disk brakes.

The 96+ spindles will be 8mm wider and likely have uncorrectable bumpsteer. 94-95 spindles will be more ideal

You cant use the booster/MC off the '98 unless you feel like converting to hydroboost. You will need a 94-95 GT MC and a 93 cobra or 94-95 SN95 booster
 
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KRUISR

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The rear axle will be 0.75" wider each side due to the disk brakes.

The 96+ spindles will be 8mm wider and likely have uncorrectable bumpsteer. 94-95 spindles will be more ideal

You cant use the booster/MC off the '98 unless you feel like converting to hydroboost. You will need a 94-95 GT MC and a 93 cobra or 94-95 SN95 booster
Mostly correct there 5L5...

The rear axle is wider because of the axle shafts are longer, not due to disc brakes. SN95 disc brake components will work on a fox axle housing with fox length axles.

96+ spindles can work on a fox without bump steer kit and/or bump steer issues. It does take a little work though. (I am using '01 spindles with no issue).

IF taking front and rear calipers from the '98, I would absolutely use the '98 master cylinder and proportioning valve. Agree a '94-'95 booster should be used.
 

Mustang5L5

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Well technically they are longer due to needing clearance for the ABS tone rings, but splitting hairs
 
Sep 2, 2017
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Well technically they are longer due to needing clearance for the ABS tone rings, but splitting hairs
OK guys thx. So I have read all kinds of things. Can I use the 98 GT rack and spindles ? I know I have read before about using different rims and using the 98 rear axle. For conversation sake I have a set of 05 5 spoke like Mustang5L5's avatar..... Thx guys....
 

Mustang5L5

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Well the BS on the 05+ wheels is deeper than the 99-04 versions like I have. But, that deeper offset will be beneficial with the wider axle. I run SN95 lenght axles on my car.

yes, you can use the steering rack.

yes, you can use the spindkes BUT, the 96-04 spindkes were meant to be used with a 96-04 K-member. The steering rack on the newer cars is 1” lower, so the mount points on the spindkes were lowered 1” to match. If you run these spindkes with a stock 79-95 k-member you end up with uncorrectable Bumpsteer.

for that reason, 94-95 spindkes are recommended
 
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Thx for the response. So is the K member from the 98 usable on the 79 ? I would need it for the engine mounts....And if the 98 K member is usable then the steering rack would be transferable also ? And to further complicate things I would like to transfer the tilt steering.....And then in doing that can I use the Master Cylinder from the 98. Thx
 

Mustang5L5

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No, you cannot bolt a 302 to a 98 K-member. It’s not usable.

the 98 steering rack will work fine with fox mustangs on the fox k member. I have an SN95 rack in my car. The downside is you need a $250 steering shaft adapter to install it using the fox column. No idea how to install the SN95 column.

98 GT MC is designed to bolt into the hydroboost using. You can install the hydroboost in a fox, but it’s a big project (I have it in my car). For the 98 GT brakes, you want a 94-95 GT master cylinder. They are relatively cheap. I believe maximum motorsports sells the adapter brake lines to connect it to your 79 prop valve
 

MustangIIMatt

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No, you cannot bolt a 302 to a 98 K-member. It’s not usable.

the 98 steering rack will work fine with fox mustangs on the fox k member. I have an SN95 rack in my car. The downside is you need a $250 steering shaft adapter to install it using the fox column. No idea how to install the SN95 column.

98 GT MC is designed to bolt into the hydroboost using. You can install the hydroboost in a fox, but it’s a big project (I have it in my car). For the 98 GT brakes, you want a 94-95 GT master cylinder. They are relatively cheap. I believe maximum motorsports sells the adapter brake lines to connect it to your 79 prop valve
If I read his first post right, he's using the 4.6 from the '98, which means the '98 k-member would work.
 
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Mustang5L5

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Ah. Yes. Good catch. Yes, using the 4.6L you’ll want to use the 98 K-member. In that case you can use the spindles.

For the brakes though, you won’t be able to fit a vacuum booster, so you either need to swap in the hydroboost, or run manual brakes
 
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So I can use the 98 K member, what other parts can I use from the 98 ? Rack and pinion, tilt steering wheel column, 5 lug hubs/spindles. Understand this I have NO concerns with keeping this thing stock. A 79 Mustang Pace Car is a gutless POS at a robust 125 hp or there abouts. Also back to the rear end it seems as though I can remember reading about using later model rims to eliminate the extra stance of the 98 rear axle. I have a set of 05 5 spoke rims which I believe will do the trick but it's been 15 years since I started collecting stuff for this project and I really would like to get started on it towards Spring... Thx for your help....Dave
 

Mustang5L5

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K member, rack and spindkes are a yes. Entire rear if you wanted as well if you pay attention to wheel offsets.

you can also buy offset csliper brackets and axles to pull the offset back in .
 
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This is a pace car?
Or were you using that as an example of the awesome power available in 1979?
Yes it is a Pace Car. A female friend of mine bought it new and I purchased it from her in the early 90's. It's been sitting in my barn since then. It has 105,000 on it. And yes it is a semi rare car but in 79 as I said before it was a gutless turd. It is a 5.0 4 speed with the Sunroof.
 
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90sickfox

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Don't forget to get the rear parking brake cables and the spot riveted bracket the cables go into in the transmission tunnel. The 79 has a different brake handle so not sure if the adjustable cable adapter will work. Not hard to fabricate something though.
 
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