Author Topic: 69-70 Trans Am Disc brake conversion. Anyone done one?  (Read 404 times)

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Offline 67428GT500

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69-70 Trans Am Disc brake conversion. Anyone done one?
« on: February 17, 2019, 04:25:10 pm »
I am looking to see what factory rotors and caliper mounting bracket that was used with the Boss 302 brake conversion as listed in the modification book.

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Offline crossboss

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Re: 69-70 Trans Am Disc brake conversion. Anyone done one?
« Reply #1 on: February 18, 2019, 11:51:46 pm »
I am looking to see what factory rotors and caliper mounting bracket that was used with the Boss 302 brake conversion as listed in the modification book.

                                                                                                                     -Keith



Lincoln spindles, rotors and calipers.
<My old C.J. heap  aka  S-B Racing!
Current lifelong project: 1969 Mustang Fastback/FOX chassis, Powered by a modern Can-Am 494 (Boss 429), Kaase headed, Autolite 1425 cfm 'B' Inline carb, 6 speed, 4 wheel discs, ala Trans-Am style--Whew!

Offline 428 CJ hardtops

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Re: 69-70 Trans Am Disc brake conversion. Anyone done one?
« Reply #2 on: February 19, 2019, 09:16:53 am »
I think the rotors were C8AZ Calaxie part numbered , sold a bunch of them to a guy years ago that was building a clone .
had many 428 CJ and SCJ cars over the last 30 years.I currently own a 68 1/2 coupe and a 69 R code SCJ Coupe and a 70 R code SCJ Cougar Eliminator .I am looking for a 70 428 coupe if anybody knows of one for sale.

Offline crossboss

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Re: 69-70 Trans Am Disc brake conversion. Anyone done one?
« Reply #3 on: February 19, 2019, 03:49:11 pm »
Here is a picture of the 'Larger' 12 inch rotors with the Lincoln 4 piston calipers. The stock production disc brake is on the right. Btw, you can adapt these to Mustang drum brake spindles. However, the Trans-Am teams used the big (stronger) Lincoln spindles with an adapter for the lower ball joints.
Click on pic to enlarge.

<My old C.J. heap  aka  S-B Racing!
Current lifelong project: 1969 Mustang Fastback/FOX chassis, Powered by a modern Can-Am 494 (Boss 429), Kaase headed, Autolite 1425 cfm 'B' Inline carb, 6 speed, 4 wheel discs, ala Trans-Am style--Whew!

Offline 67428GT500

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Re: 69-70 Trans Am Disc brake conversion. Anyone done one?
« Reply #4 on: February 20, 2019, 05:30:34 am »
They never used lincoln spindles.   They use lincoln, T-bird or Galaxie calipers. It uses either the 65-7 spindle or the 70 drum brake spindle. Two companies offer the conversion. Cobra Automotive and one other. It's 2200.00 from them.  Rediculous.  I am just trying to keep my vehicle looking more period. The rotors are almost 1.250 inches wide and they are viened to direct air.  I know someone went through this on another forum and figured out that LTD rotors  with the lincoln calipers, they machine the caliper adapters, but those are 433.00.
I was hoping someone sourced parts to complete the conversion without getting into it Wilwood front and rear disc prices with a race master cylinder.
Once you have tasted flight, you will forever walk the earth with your eyes turned skyward. For there you have been, and there you will always long to return.
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Offline crossboss

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Re: 69-70 Trans Am Disc brake conversion. Anyone done one?
« Reply #5 on: February 20, 2019, 10:49:19 am »
They never used lincoln spindles.   They use lincoln, T-bird or Galaxie calipers. It uses either the 65-7 spindle or the 70 drum brake spindle. Two companies offer the conversion. Cobra Automotive and one other. It's 2200.00 from them.  Rediculous.  I am just trying to keep my vehicle looking more period. The rotors are almost 1.250 inches wide and they are viened to direct air.  I know someone went through this on another forum and figured out that LTD rotors  with the lincoln calipers, they machine the caliper adapters, but those are 433.00.
I was hoping someone sourced parts to complete the conversion without getting into it Wilwood front and rear disc prices with a race master cylinder.



With all due respect, Lincoln spindles were used on T/A cars. Some also had special Kar Kraft versions (factory team cars). Lincoln or 'big car' rotors (with 5X5 wheel mounting), and 4 piston calipers. Cobra automotive and others do make such 'conversions' using drum spindles, for ease of adapters and removable hubs. Also, some independent (private) cars used the drum spindles for cost savings/weight saving over the 'big' (and heavy) Lincoln/KK versions. I know, I vintage raced a T/A Boss.
Now, that said, I would go the modern route. Lighter, better, newer….just me.
Another suggestion, go over to the Boss 302 site under the Trans Am section.
<My old C.J. heap  aka  S-B Racing!
Current lifelong project: 1969 Mustang Fastback/FOX chassis, Powered by a modern Can-Am 494 (Boss 429), Kaase headed, Autolite 1425 cfm 'B' Inline carb, 6 speed, 4 wheel discs, ala Trans-Am style--Whew!

Offline sportyworty

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Re: 69-70 Trans Am Disc brake conversion. Anyone done one?
« Reply #6 on: February 20, 2019, 11:39:17 am »
with all due respect to boot ! ;D
gotta be 100 posts on Boss Forum
crossboss is a reliable source of info or he does not post 8)
8F91R577646  Black 4 Speed

Offline 161854

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Re: 69-70 Trans Am Disc brake conversion. Anyone done one?
« Reply #7 on: February 20, 2019, 01:14:11 pm »
       Scott,
          YOU owe 67428GT500 an apology. Lincoln spindles were NEVER used on a Mustang. #1 , they won't fit . #2 they wouldn't need a caliper adapter IF they did. The original DOZX caliper brackets are designed  to adapt Lincoln calipers to MUSTANG spindles. Kar Kraft spindles were strengthened and altered geometry MUSTANG spindles.
       Randy
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Offline 161854

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Re: 69-70 Trans Am Disc brake conversion. Anyone done one?
« Reply #8 on: February 20, 2019, 01:31:08 pm »
   Keith,
      The DOZX ( the part number they were sold under) caliper brackets were unique Kar Kraft designed parts.  I helped with the restoration of the '69 Kar Kraft prototype built for Shelby Racing Co. ( "073") and it had KKX "Mustang" spindles and the caliper adapters ( with KKX numbers). Some of my friends have made their own from billet steel by copying originals which were forgings. I do know of one guy that adapted '65T Bird spindles to the Mustang control arms but the geometry was less than ideal.
   Randy
68 1/2 CJ FB San Jose white/blue "C" stripe Foulger Ford
 66 GT350 Hertz SFM 6S 477 white/ blue side stripes 1  of 18
3 magazine covers- Car Craft July '77,  Modified Mustangs Feb '11 , and June '14 Mustang Monthly
'78 F350 Oleynik racecar hauler

Offline crossboss

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Re: 69-70 Trans Am Disc brake conversion. Anyone done one?
« Reply #9 on: February 20, 2019, 01:41:30 pm »
       Scott,
          YOU owe 67428GT500 an apology. Lincoln spindles were NEVER used on a Mustang. #1 , they won't fit . #2 they wouldn't need a caliper adapter IF they did. The original DOZX caliper brackets are designed  to adapt Lincoln calipers to MUSTANG spindles. Kar Kraft spindles were strengthened and altered geometry MUSTANG spindles.
       Randy



Randy,
You know I respect your 'expert' advice, however, again with all due respect, some racers did use Lincoln spindles. Most, as you mentioned used the KK stuff. I believe your misunderstanding what I was referring to, the 'adapter' (or ball joint spacer) that I mentioned was not for the brake stuff, it was for the lower ball joint as the Lincoln spindle is larger in diameter for the Mustang. Spacers/adapters were used to 'fill in' the difference. I have seen it otherwise I would not have said so. I guess we have a difference of opinion. No hard feelings!
« Last Edit: February 20, 2019, 01:48:14 pm by crossboss »
<My old C.J. heap  aka  S-B Racing!
Current lifelong project: 1969 Mustang Fastback/FOX chassis, Powered by a modern Can-Am 494 (Boss 429), Kaase headed, Autolite 1425 cfm 'B' Inline carb, 6 speed, 4 wheel discs, ala Trans-Am style--Whew!

Offline 161854

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Re: 69-70 Trans Am Disc brake conversion. Anyone done one?
« Reply #10 on: February 20, 2019, 05:51:57 pm »
    Scott ,
       Independents did some creative stuff , I agree . Yes the fellow that did the T Bird spindle deal used ball joint spacers ( you may remember Tom Butke rip)but the geometry was not good. My only point of correction is the factory using Lincion spindles which "they" did not do.
     Keith's specific question was what factory rotors and caliper brackets were used . Caliper brackets would not be needed if a Lincoln spindle was used as the mounting would already BE there. Nothing was mentioned about the spindle. In actuality NONE of the front suspension components were "stock , production" parts. EVERY part was different than production with the possible exception of some of the bolts. Curved vane  (mehanite in some cases) rotors , modified A arms , adjustable ball joints , "do it yourself " drag links ( for zero bump steer) , the altered KKX spindles , solid spacers for the wheel bearing preload , spherical balls used on the control arm pivots and strut rods and whatever else I can't remember.  The move to a 5" bolt circle was an attempt to solve the center of the 200S wheels  cracking.
   We're good as always.
68 1/2 CJ FB San Jose white/blue "C" stripe Foulger Ford
 66 GT350 Hertz SFM 6S 477 white/ blue side stripes 1  of 18
3 magazine covers- Car Craft July '77,  Modified Mustangs Feb '11 , and June '14 Mustang Monthly
'78 F350 Oleynik racecar hauler

Offline 67428GT500

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Re: 69-70 Trans Am Disc brake conversion. Anyone done one?
« Reply #11 on: February 21, 2019, 12:26:14 am »
There is a parts list in the Boss 302 Chassis book. There was NO mention of anything other than using the 4 bolt 70 mustang drum spindle. The parts list was there in the book by ford part number. The Lincoln spindle won't fit on Mustang control arms. I am not saying there wasn't something that was played with.  The K/H calipers use a cast adapter bracket that required modification.
I have a 1967 GT 500. I just don't want to stray too far from the vintage look.
Cobra Automotive sells the kit as does one other.  As explained, I would rather have the vintage look than putting something like Wilwoods on my Shelby.
I don't want to be rude. I am just trying to sort it out. Another group did. I just can't find the thread. 500+ HP doesn't stop well with factory disc/ 10X2.5 drums.
I do thank everyone for the input.  Just have to sort out the details. I will share them here once I have all the information.

http://store.cobraautomotive.com/100-3000-competition-12-front-brake-kit/
Once you have tasted flight, you will forever walk the earth with your eyes turned skyward. For there you have been, and there you will always long to return.
"If It's Not Boeing, I'm Not Going!"

Offline crossboss

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Re: 69-70 Trans Am Disc brake conversion. Anyone done one?
« Reply #12 on: February 21, 2019, 10:31:00 am »
    Scott ,
       Independents did some creative stuff , I agree . Yes the fellow that did the T Bird spindle deal used ball joint spacers ( you may remember Tom Butke rip)but the geometry was not good. My only point of correction is the factory using Lincion spindles which "they" did not do.
     Keith's specific question was what factory rotors and caliper brackets were used . Caliper brackets would not be needed if a Lincoln spindle was used as the mounting would already BE there. Nothing was mentioned about the spindle. In actuality NONE of the front suspension components were "stock , production" parts. EVERY part was different than production with the possible exception of some of the bolts. Curved vane  (mehanite in some cases) rotors , modified A arms , adjustable ball joints , "do it yourself " drag links ( for zero bump steer) , the altered KKX spindles , solid spacers for the wheel bearing preload , spherical balls used on the control arm pivots and strut rods and whatever else I can't remember.  The move to a 5" bolt circle was an attempt to solve the center of the 200S wheels  cracking.
   We're good as always.



Randy,
Yes, we are long time friends and are always good! FWIW, I had the Lincoln set up (with redrilled rotors to 5 on 4.5 bolt pattern) on my car. Now, lets move to the topic at hand…
The chassis book only mentions the drum spindle/brake swap as discussed.
<My old C.J. heap  aka  S-B Racing!
Current lifelong project: 1969 Mustang Fastback/FOX chassis, Powered by a modern Can-Am 494 (Boss 429), Kaase headed, Autolite 1425 cfm 'B' Inline carb, 6 speed, 4 wheel discs, ala Trans-Am style--Whew!