four lug spindle 1965 Mustang

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Ger47

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Sep 21, 2020

#1

• Sep 21, 2020

• #1

Fellow members. I am new to this forum. Just bought a 1965 Mustang FB, inline 6 with C4 tranny, that Initially would like to improve the brakes and suspension. The spindles are four lugs and in reading it seems that the four lug spindle is too weak for disc brake upgrade. All indications carry me to purchase a new1965 or 1966 V8 spindle, but the mod would introduce changes to the steering.
Can some one comment on their experience in doing this.
A reply is appreciated.
Ger47

 

wicked93gs

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Sep 22, 2020

#2

• Sep 22, 2020

• #2

4 lug spindles are not too weak for disc brakes...there are several kits out there designed to fit 4 lug spindles right now. That being said, neither the factory I6 or the factory v8 spindles are very good for heavy cornering...but for normal driving, most people like to upgrade to the v8 spindles. Differences between steering setup for I6 and v8:



left is v8, right is I6...pretty much every component is different.(Early 65 production v8s shared the I6 steering from my understanding, but don't quote me on that) As you can see, the I6 tie rods are shorter...meaning I6 spindles have longer steering arms(or so I would assume).

In short...its more complicated than just a spindle swap. For those who race vintage mustangs, they like to actually use 69-70 spindles, which are stronger under the stress of high speed cornering.

 

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Ger47

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Sep 23, 2020

#3

• Sep 23, 2020

• #3

Thank you for your prompt reply. So what options I have if I want to convert to a five lug spindle as the options for five lug wheels is a lot more that for a four lug.
Would this means that I have to upgrade the steering components?
Appreciate your comments

 

wicked93gs

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Sep 23, 2020

#4

• Sep 23, 2020

• #4

The question you need to answer is what are your ultimate goals for the car? There are a lot of 4-lug options out there...you are just looking in the wrong places:



Konig Rewind for instance is a Minilite-style wheel available in a variety of sizes and backspacing in 4x114.3(4x4.5"). This is a wheel you usually see on vintage European or Japanese cars but looks great on just about everything, vintage mustangs included.



The ones I linked above are available in 15x7 4x114.3 and 4" backspacing for $110 a piece...if you look you can find them in a lot of different sizes, backspacing, and bolt patterns. The point being that there are a LOT of 4x114.3 wheels out there...but they are often marketed more toward imports. As far as converting to 5-lug goes, your first question needs to be how you are going to use the car.....if you plan to just drive it fairly normally, 4 lugs and stock spindles will be just fine. If you plan to road-race or autocross the car, then you should be looking at the larger 69-type spindles....somewhere in-between you should be looking at v8 spindles. once you narrow down spindle choice, then you can start looking at brake kits.

 

rbohm

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Sep 23, 2020

#5

• Sep 23, 2020

• #5

if you just want front disc brakes for your four lug car, then either buy a complete kit sold at many suppliers, like NPD, or go to scarbird mechanical and get their bracket kit and buy the parts they list. it all goes together nicely as many have noted at fordsix.com. the six cylinder spindle is strong enough to handle any normal, and even some high performance driving you can toss at them.

as wicked noted, the V8 spindles are much stronger, and can handle being used in racing at pretty high levels, as shelby did in the mid 60s. by the way, ford went to a stronger/larger spindle in 1970. but as wicked also noted, you need to change to the V8 steering linkage. and dont forget that you also need to change the rear end to a five lug system if you want five lug wheels.

 

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Ger47

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Sep 23, 2020

#6

• Sep 23, 2020

• #6

Thanks for your reply and eye opener. I will pursue continuing with the four lug and converting to disc brakes.

Thank you for your time and advise.

Regards,
Ger47

 

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Ger47

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#7

• Sep 23, 2020

• #7

Hope this is the last question, what size disc rotor would you recommend for the upgrade?

Appreciate your input.

 

rbohm

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Sep 23, 2020

#8

• Sep 23, 2020

• #8

i think scarebird uses an 11" rotor. for day to day driving that will be sufficient.

 

wicked93gs

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Sep 24, 2020

#9

• Sep 24, 2020

• #9

I agree with rbohm, its a sub-3000lb car...an 11" rotor should be fine....but wheel size ties into your choice there(11" rotors look kinda goofy if using 18" wheels...though I personally would not go above a 16" wheel on a 65-66, they start looking cartoonish at a certain point)

 

Reactions: rbohm

rbohm

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Sep 24, 2020

#10

• Sep 24, 2020

• #10

wicked93gs said:

I agree with rbohm, its a sub-3000lb car...an 11" rotor should be fine....but wheel size ties into your choice there(11" rotors look kinda goofy if using 18" wheels...though I personally would not go above a 16" wheel on a 65-66, they start looking cartoonish at a certain point)

Click to expand...

agreed. i think the largest wheel that should be used on a vintage car is 17", 18s on trucks.

 

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Ger47

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Oct 12, 2020

#11

• Oct 12, 2020

• #11

Thank you for your advice.
I have decided to upgrade the steering with a Flaming River system and also upgrade the suspension with Street or Track system. I would appreciate it if you could give some guidance as to what to upgrade first after upgrading the brake system to front and rear discs.

Your comments and recommendations are appreciated.

 

wicked93gs

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Oct 21, 2020

#12

• Oct 21, 2020

• #12

Street or Track makes a great coilover system....but if you are going to that extreme, then you will find many of the braking kits he offers are for v8 spindles. Ideally you would want to pair his suspension system with his braking system since Shaun tunes that stuff to work together himself on the track. I think he even sells the new CPP spindles on his website. Of course the I6 spindles will work....but they are pretty outclassed by the suspension at that point. I myself am going to order his coilover kit swithin the next month or so...I plan to start there, then at a later point get rear coilover system and braking upgrades too. You might be interested in this article about his braking system, just keep in mind for those rotors you need 17" wheels:

Street/Track Vintage Mustang Brake Upgrade

We install and test before and after effects of Street or Track’s brake upgrade for early Mustangs

www.hotrod.com

 

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Ger47

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#13

• Oct 22, 2020

• #13

Thank you for your comments

 

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Ger47

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#14

• Nov 22, 2020

• #14

Gentlemen, back for some of your wise advise.
My 1965 FB has the stock differential with a 2.83 gear ratio. I would like to install a five speed manual trans, but with the existing stock differential I would have to reach 75 to 80 MPH before I could get it in fifth gear. Would like to install a 3.25 gears in the existing differential. Is this feasible or do I need a new axle?
Your comments are appreciated.

 

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Ger47

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Dec 5, 2020

#15

• Dec 5, 2020

• #15

Ger47 said:

Gentlemen, back for some of your wise advise.
My 1965 FB has the stock differential with a 2.83 gear ratio. I would like to install a five speed manual trans, but with the existing stock differential I would have to reach 75 to 80 MPH before I could get it in fifth gear. Would like to install a 3.25 gears in the existing differential. Is this feasible or do I need a new axle?
Your comments are appreciated.

Click to expand...

Stock rear end differential. Appreciate a comment from someone. THanks

 

wicked93gs

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Dec 7, 2020

#16

• Dec 7, 2020

• #16

Well, it depends on what you mean by feasible. You can buy 3.73s for the stock 7.25" 6 cylinder rear from Jegs(the guys over at ford6 do this occasionally)...as to whether its worth it, for a cruiser I would say it probably is...just don't expect the 7.25" rear to hold up to a lot of power and abuse. I myself only swapped to an 8" because I didn't care for the idea of an 8.8 or 9...added weight for no reason for my power level.

 

G

Ger47

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Dec 11, 2020

#17

• Dec 11, 2020

• #17

wicked93gs said:

Well, it depends on what you mean by feasible. You can buy 3.73s for the stock 7.25" 6 cylinder rear from Jegs(the guys over at ford6 do this occasionally)...as to whether its worth it, for a cruiser I would say it probably is...just don't expect the 7.25" rear to hold up to a lot of power and abuse. I myself only swapped to an 8" because I didn't care for the idea of an 8.8 or 9...added weight for no reason for my power level.

Click to expand...

Thanks for your reply