1969-70 Trans Am disc brake conversion.

[1967 eight barrel]

The Boss 302 modification book has a conversion to lincoln fron calipers, 12" disc. Has anyone done the conversion from ford components. What will I need.  Yes, I know Cobra automotive offers their version. 2200.00 is rediculous.

[Krelboyne]

I have sold Cobra Automotive maybe a dozen sets of big Ford car, Kelsey-Hayes 4 piston disc brake calipers and 1970 drum brake spindles over the years. I mostly found the calipers on 1966-67 Ford Thunderbird, but sometimes Lincoln.
Cobra Automotive makes the adapter bracket to fit Ford small or large drum brake spindles.
The large bearing drum brake spindles have a D0.. casting number. I used to find them on 1970 Mustang, Cougar, and B/C body Ford / Mercury cars.

[Bob Gaines]

I have sold Cobra Automotive maybe a dozen sets of big Ford car, Kelsey-Hayes 4 piston disc brake calipers and 1970 drum brake spindles over the years. I mostly found the calipers on 1966-67 Ford Thunderbird, but sometimes Lincoln.
Cobra Automotive makes the adapter bracket to fit Ford small or large drum brake spindles.
The large bearing drum brake spindles have a D0.. casting number. I used to find them on 1970 Mustang, Cougar, and B/C body Ford / Mercury cars.

Don't forget the rotor which is a special combination as well.

[1967 eight barrel]

Cobra Automotiveis using what appears to be Wilwood hats and rotors with the lincoln/T-bird/Galaxie large Kelsey Hayes calipers. I understand that 70 0r 71 LTD rotors go directly on the spindel and billet disc brake caliper mounts ( A whopping 433.00) are directly mounted. The calipers are easily found and reasonable.  I just wanted the vintage look on the vehicle.  Wilwood offers a great set up for about 750.00. 2100.00 is redicuous.
                                                                                                                                             -Keith

[67411F--0100-ENG.]

Hello Keith,

I believe this should get you close:

1. 1970 Mustang drum brake spindles.
2. 1970 Mustang disc brake hubs.
3. Caliper mounting brackets from Cobra Automotive.
4. 1965-1967 Lincoln/T-Bird calipers.
5. Raybestos 6008 rotors.
6. 1970 Mustang outer tie rods.

Here is a link to an article that talks about this conversion:

http://www.mustangandfords.com/how-to/wheels-tires/mdmp-1103-1969-ford-mustang-boss-302-trans-am-brake-swap/

I hope this helps.


Thanks,
Eric

[1967 eight barrel]

Eric,  Is it necessary to change spindles? 

[67411F--0100-ENG.]

Hello Keith,

Yes, I believe it is.  I do not think all of the other parts will work with stock '67 disc brake spindles.  Plus, the '70 drum brake spindles use larger bearings because the stub shaft is bigger/stronger.

Thanks,
Eric

[1109RWHP]

Don't forget 67 Mustang disc brake hubs. The 6008 rotors do not have integral hubs.

[1967 eight barrel]

Well, I'm just in luck!  I have '67 disc brakes on my Shelby! lol   I gather Master Power Brakes has the modified Ford mounting brackets.

                                                                                                     -Keith

[1109RWHP]

Not sure but Street or Track has them for 399.00.

[1967 eight barrel]

Cobra automotive and Street and track have them. Cobra Automotive is 433.00. 399.00 at Road and Track. I am pretty sure the OE ford that Master Power modifies and uses will be much less expensive.  2,200.00 for the kit is rediculous.  The only reason I am not going Wilwood is because they look OE.

                                                                                                           -Keith

[1109RWHP]

If you find a part number for the MP. ones I would like to see them.

[shelbydoug]

I did the swap. You need the special adapters to go from the 70 spindles to the tbird calipers. Those are not Ford parts. I got those from Cobra Automotive.

I'm not sure about the hubs though. I thought they needed to go to the big bearing 70 hubs.

If you want to run 10 spokes, you need to switch to the current reproductions. Those are machined on the back. The originals are not and will not clear the calipers.

You also need to space the caliper back around 1/8" with hardened washers and use a 1/8" wheel spacer in front. The spacing is done to fit the 10 spokes.

I switched to long comp wheel studs. They will fit the special Shelby wheel lugs.

[1967 eight barrel]

Doug, The Boss 302 book showed all ford part numbers for the conversion. Cobra Automotive is a rip off at 2100.00  They also don't use ford rotors, but some combination that appear to be Wilwood rotors and hats. I have to pick up the Boss 302 chassis book again. I beleive the Lincoln mounting brackets are simply re-drilled.  I may buy the caliper brackets from Cobra Automotive, but 433.00 is pretty steep.   I am not running the 15" 10 spokes, so there is no issue. They are 17" and a 4.5" offset.   Did you find there was a noticable difference in braking with the 12" change over? 

                                                                                                                     -Keith

[shelbydoug]

Doug, The Boss 302 book showed all ford part numbers for the conversion. Cobra Automotive is a rip off at 2100.00  They also don't use ford rotors, but some combination that appear to be Wilwood rotors and hats. I have to pick up the Boss 302 chassis book again. I beleive the Lincoln mounting brackets are simply re-drilled.  I may buy the caliper brackets from Cobra Automotive, but 433.00 is pretty steep.   I am not running the 15" 10 spokes, so there is no issue. They are 17" and a 4.5" offset.   Did you find there was a noticable difference in braking with the 12" change over? 

                                                                                                                     -Keith

That adapter is a Kar Kraft part. It was never in the Ford Parts Book. Yes the adapters are expensive. They've lowered their price because several people are making the adapters. I paid $600 for them, maybe $550, when they were the only source.


Is there a noticeable difference in braking? No. The value of the system is that the big rotors cool off faster BUT part of the issue is the Porterfield pads.  You have to get them HOT!

I think one of the magazines did a comparison test and this set up was 30 or 40 feet shorter coming down from 100 and something? Maybe Mustang Monthly? Don't remember that specifically at the moment.



The other thing is that you need to mess with the master cylinder. They work MUCH better with the manual brakes and the 1-1/8" bore master. You can't  use that with power brakes. It won't work with it.

The master for the power brakes is a 1" bore. With that set up they feel about the same as the stock calipers but I haven't tried them on the track as of yet. I think that the issue, if there is an issue, is that they are intended to have the crap beat out of them to make them work right.

They were designed for Trans Am racing and if you never saw that live, it was like an attempt at mass automotive suicide. Those guys were nutzzz!



They probably would have a better feel with regular heavy duty pads. I can't confirm that though since I haven't tried those.

I will point out that the T/A cars ran regular production brakes until someone at Kar Kraft engineered these for the Boss 302's for the 69 season.



Additional braking would be gained by increasing the od of the rotors. Something you need a larger wheel for but then, you are going to need to mess with the proportioning valve beyond what anyone has done with them as far as I know? I put the 65 adjustable unit in and it was good out of the box. What you would need to do for 14" rotors I don't know.



I wasn't telling you what to do, just warning everyone contemplating this swap who intended to use the 10 spokes. No one told me about it until I was into it. I ask Voght at Cobra Automotive and he said something like, "oh yea, I forgot to tell you that, but don't worry, we already did three '67s and all you need to do is machine the wheels".


Oh, you need to machine the reinforcing vein off of the face of the caliper to make it clear just about any wheel and you need to drill out the threads for the mounting bolts and reverse them. The left caliper goes on the right side and the right on the left side.