# Disc brake conversion



## Tim68 (Dec 1, 2019)

Did the front di brake conversion with a 2” drop today. Went well and very please with the quality of the CPP set. Now have 3/4” rake from rear to front. No rubbing on my test drive.
Highly recommend this system.


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## PDub (Sep 8, 2019)

Tim68 said:


> Did the front di brake conversion with a 2” drop today. Went well and very please with the quality of the CPP set. Now have 3/4” rake from rear to front. No rubbing on my test drive.
> Highly recommend this system.


Do you have photos to share? Curious on how a 2" drop in the front looks. I was considering a 1" drop but not sure it will give me the look I want.


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## Tim68 (Dec 1, 2019)

This is not a great picture 
It’s raining today, I’ll try to get a better pic when weather permitting


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## gtojoe68 (Jan 4, 2019)

Tim68 said:


> This is not a great picture
> It’s raining today, I’ll try to get a better pic when weather permitting


Curious where you had wheels made? Or are those really rally2 wheels? Look great


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## Tim68 (Dec 1, 2019)

gtojoe68 said:


> Curious where you had wheels made? Or are those really rally2 wheels? Look great


Wheels are from Original Parts Group 
17”. They look very much like rallies but are all aluminum


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## Tim68 (Dec 1, 2019)

Tim68 said:


> Wheels are from Original Parts Group
> 17”. They look very much like rallies but are all aluminum





https://www.opgi.com/wheels-accessories/wheels/grand-prix-aluminum-rally-ii-wheels/rally-ii-wheel-1964-73-gto-aluminum-17x8-4-12-bs-g241982.html


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## PontiacJim (Dec 29, 2012)

Tim68 said:


> Did the front di brake conversion with a 2” drop today. Went well and very please with the quality of the CPP set. Now have 3/4” rake from rear to front. No rubbing on my test drive.
> Highly recommend this system.


CPP = *C*lassic *P*erformance* P*roducts. They seem to offer a number of assorted parts and/or kits in various stages depending on your needs. The is no page specific to the Pontiac A-body, but Chevelle is the same, but always email/call to confirm you are getting the correct parts for your car.

They also have other individual brake parts, steering/suspension components, transmissions/crossmembers, and other parts and you can do a search for the tech PDF's and installation guides which can be helpful in understanding the product or simply comparing to other brands.






1964-1972 Chevelle / El Camino Parts. The Finest in Suspension, Brakes, Steering and Accessories.


Classic Performance Products parts for classic 1947-1955 Chevy Chevelle and El Caminos



www.classicperform.com


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## armyadarkness (Dec 7, 2020)

Tim68 said:


> Wheels are from Original Parts Group
> 17”. They look very much like rallies but are all aluminum


OMG, how is @Baaad65 not in here posting pics of his rims?


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## PontiacJim (Dec 29, 2012)

armyadarkness said:


> OMG, how is @Baaad65 not in here posting pics of his rims?


Argh! Just give him time to wake up from his nap and he'll be posting - key words "17" rims", "1965 GTO", "pics of 1965 GTO", "best 17" tire size", "engine pics," "valve cover breathers,"....... Hey *Army*, how do you set your Forum settings for key words/phrase alerts like *Baaad65* has on his I-phone? 😂


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## aseyc (Aug 26, 2020)

Tim68 said:


> https://www.opgi.com/wheels-accessories/wheels/grand-prix-aluminum-rally-ii-wheels/rally-ii-wheel-1964-73-gto-aluminum-17x8-4-12-bs-g241982.html


Very nice wheels you got there. Can you show a side shot to see how they sit in terms of offset? Are the front and rear the same or are they staggered?


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## Baaad65 (Aug 29, 2019)

armyadarkness said:


> OMG, how is @Baaad65 not in here posting pics of his rims?





PontiacJim said:


> Argh! Just give him time to wake up from his nap and he'll be posting - key words "17" rims", "1965 GTO", "pics of 1965 GTO", "best 17" tire size", "engine pics," "valve cover breathers,"....... Hey *Army*, how do you set your Forum settings for key words/phrase alerts like *Baaad65* has on his I-phone? 😂


Oh I'm awake don't you worry 😉


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## Tim68 (Dec 1, 2019)

aseyc said:


> Very nice wheels you got there. Can you show a side shot to see how they sit in terms of offset? Are the front and rear the same or are they staggered?


They are all 17” 
rear 9” with 275/40
front 8” with 255/40
ill get a good picture this weekend and post


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## aseyc (Aug 26, 2020)

Tim68 said:


> They are all 17”
> rear 9” with 275/40
> front 8” with 255/40
> ill get a good picture this weekend and post


Great, would be also interesting to know which kit from CPP you used as I have drums but i am really interested in going disk on the front which apparently also changes offset.


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## armyadarkness (Dec 7, 2020)

Baaad65 said:


> Oh I'm awake don't you worry 😉


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## armyadarkness (Dec 7, 2020)

I do really like those wheels. I prefer to stick with 15's, but Id get them in a minute if my Rally 2's ever needed paint


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## aseyc (Aug 26, 2020)

Tim68 said:


> They are all 17”
> rear 9” with 275/40
> front 8” with 255/40
> ill get a good picture this weekend and post


Hey Tim68. Did you find some time to take some pics for us?


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## Tim68 (Dec 1, 2019)

aseyc said:


> Hey Tim68. Did you find some time to take some pics for us?


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## Tim68 (Dec 1, 2019)

Pictures 
One thing that I have recently found is that I am thinking about going with tubular a arms. I am finding that tubular a arms lower the ride height anywhere from 1”-3”. I don’t think that will work.
Anyone have experience with a 2” spindle drop and tubular a arms?


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## aseyc (Aug 26, 2020)

Really nice wheels. Starting to favor 17s after seeing these. Would you be so kind sharing which spindles you used on the front from CPP? I am guessing that the rears are stock drum from the photos.

Cant help you re tubular a-arms. But why would you want to go that route anyway?


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## Tim68 (Dec 1, 2019)

aseyc said:


> Really nice wheels. Starting to favor 17s after seeing these. Would you be so kind sharing which spindles you used on the front from CPP? I am guessing that the rears are stock drum from the photos.
> 
> Cant help you re tubular a-arms. But why would you want to go that route anyway?


I have ordered the rear but they were back ordered 
I used the 2” drop spindles
Still have the original front and rear springs


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## O52 (Jan 27, 2019)

Tubular Bottom A arms with a tall ball joint will lower the car. Just use the stock or tubular lower A arm with the stock BJ and a tubular Upper with stock BJ.. Primarily its the top arm that alters the alignment settings









1964-1972 GM A-Body Upper A-Arms, Delrin Bushings - UMI Performance Inc.


Improve handling and make your classic A-Body feel like a modern day muscle car by installing our P/N 4033 tubular




www.umiperformance.com













1964-1972 GM A-Body Tubular Lower A-Arms, Delrin Bushings - UMI Performance Inc.


Tired of looking at hammered, crusty lower a-arms with cracked ball joint bosses? UMI has the solution with brand new




www.umiperformance.com


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## Tim68 (Dec 1, 2019)

O52 said:


> Tubular Bottom A arms with a tall ball joint will lower the car. Just use the stock or tubular lower A arm with the stock BJ and a tubular Upper with stock BJ.. Primarily its the top arm that alters the alignment settings
> 
> 
> 
> ...


What’s your thoughts about front coil overs?


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## O52 (Jan 27, 2019)

No thought at all. I like em the way the dealer delivered them, lol.

Seriously I have no opinion. I have made some improvements to my 68's suspension, but they would be hard to see. It still has all the hard parts it was born with.

My previously owned El Camino SS had a UMI suspension. I like UMI. Parts are well made and really improved the handling of the cruck. 

The GTO was my moms car and it's being restored the way it came home from the dealer with a few additional options (AM/FM, Clock and Pwr Steering). She's waiting for me to finish it so she can drive it once again.


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## Tim68 (Dec 1, 2019)

aseyc said:


> Great, would be also interesting to know which kit from CPP you used as I have drums but i am really interested in going disk on the front which apparently also changes offset.


CH28815 is the part number


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## Noangelbuddy (Dec 6, 2017)

aseyc said:


> Really nice wheels. Starting to favor 17s after seeing these. Would you be so kind sharing which spindles you used on the front from CPP? I am guessing that the rears are stock drum from the photos.
> 
> Cant help you re tubular a-arms. But why would you want to go that route anyway?


I thought about tubular, assuming newer was better. Did some research and read a few horror stories about them failing while the car was in motion. One guy who made the swap said they were modern, cool looking Chinese garbage. Fortunately the guy was not hurt and re-installed the old control arms.


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## aseyc (Aug 26, 2020)

Tim68 said:


> CH28815 is the part number


Thanks for the info!! Much appreciated.


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## gtojoe68 (Jan 4, 2019)

armyadarkness said:


> I do really like those wheels. I prefer to stick with 15's, but Id get them in a minute if my Rally 2's ever needed paint


I painted mine years ago with the template kit from Ames. A lot of work. Muratic acid dip, wire wheel off the flash rust, multiple coats etc. total PITA, but they looked fab


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## gtojoe68 (Jan 4, 2019)

UMI makes great suspension products that are not Chinese crap. Expensive but nice. I installed their upgraded rear 4 link suspension pieces elected to stay with factory front. I like the 60’s look and ride height. It’s comfortable and my 4000lb convertible is never going to corner like newer muscle anyway. Nor do I care. I just wasn’t safe and reliable


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## aseyc (Aug 26, 2020)

Does anyone has good or bad experience with such kit








1968 1972 chevelle gm A body power front disc brake conversion gto red calipers | eBay


Find many great new & used options and get the best deals for 1968 1972 chevelle gm A body power front disc brake conversion gto red calipers at the best online prices at eBay! Free shipping for many products!



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Looks like 14” wheels would still fit


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## Jared (Apr 19, 2013)

Personally not crazy about cross drilled rotors, especially lower end/name brand unknown versions. You really don't need them on a street car and they can develop heat cracks where they are drilled due to inconsistent heat and cooling.


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## aseyc (Aug 26, 2020)

Jared said:


> Personally not crazy about cross drilled rotors, especially lower end/name brand unknown versions. You really don't need them on a street car and they can develop heat cracks where they are drilled due to inconsistent heat and cooling.


Thanks for your reply Jared. I fully agree with you. I dont even like the whistling noise they make. Was referring more to the rest of the kit. The spindles, calipers, brake booster…

Also what about the proportioning valve mounted to the side of the reservoir? Is it how a 68 should be?


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## aseyc (Aug 26, 2020)

This would be one without drilled rotors but I am not sure what difference it has from the other one apart from the red colored calipers.

This one also has the proportioning valve mounted beneath the master cylinder.









68-72 Gm A-Body Front Power Disc Brake Conversion Kit Set Caliper Rotor Brackets | eBay


Entdecken Sie 68-72 Gm A-Body Front Power Disc Brake Conversion Kit Set Caliper Rotor Brackets in der großen Auswahl bei eBay. Kostenlose Lieferung für viele Artikel!



www.ebay.de


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## Jared (Apr 19, 2013)

That second one supplied by Inline Tube. They have a decent reputation on here. I bought brake lines (and I think the MC) that're on mine now through them. The proportioning valve is not stock style for 1968 but was a factory style from 70s through 80s GM. Very common on the retro fit kits because they work well. I'm running the same valve on mine with a manual brake MC. Both kits look to use the same one just mounted different (brackets and lines).


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## PopsRedCar (9 mo ago)

Tim68 said:


> Did the front di brake conversion with a 2” drop today. Went well and very please with the quality of the CPP set. Now have 3/4” rake from rear to front. No rubbing on my test drive.
> Highly recommend this system.


What was the install like for this kit? I know not all kits are created equal.

Any particular reason you went with front only, over front & rear? I've seen the front/rear kits but haven't seen many threads or posts of anyone using those.


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## armyadarkness (Dec 7, 2020)

PopsRedCar said:


> What was the install like for this kit? I know not all kits are created equal.
> 
> Any particular reason you went with front only, over front & rear? I've seen the front/rear kits but haven't seen many threads or posts of anyone using those.


Rear drums work very well, so unless you hate them, there's no reason to change them...

Plus, you save a few hundred bucks and dont have to pull the rear axles.


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## PopsRedCar (9 mo ago)

armyadarkness said:


> Rear drums work very well, so unless you hate them, there's no reason to change them...
> 
> Plus, you save a few hundred bucks and dont have to pull the rear axles.


No issues with rear drums. I didn't think about having to pull rear axles.

Thanks!


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## armyadarkness (Dec 7, 2020)

I drive my car very hard and frequently, and the rear drums serve me well.

Yes, you can de-clutter and clean up with discs, but performance isnt going to improve much... Pulling the axles on BOP isnt the worst, but if you're not used to doing it, then maybe skip it...

OTOH, if youve never replaced your 50 year old axle seals and bearings, I would quickly be pulling the axles, whether you do the brakes or not. Pontiac diffs rely on the bearings to hold the axle in the car, so it's not an area to overlook.


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## PopsRedCar (9 mo ago)

armyadarkness said:


> I drive my car very hard and frequently, and the rear drums serve me well.
> 
> Yes, you can de-clutter and clean up with discs, but performance isnt going to improve much... Pulling the axles on BOP isnt the worst, but if you're not used to doing it, then maybe skip it...
> 
> OTOH, if youve never replaced your 50 year old axle seals and bearings, I would quickly be pulling the axles, whether you do the brakes or not. Pontiac diffs rely on the bearings to hold the axle in the car, so it's not an area to overlook.


I don't know the extent of what my grandfather did in regards to maintenance other than motor/trans. My guess is not much so sounds like I may have another winter project.

Thanks.


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## armyadarkness (Dec 7, 2020)

PopsRedCar said:


> I don't know the extent of what my grandfather did in regards to maintenance other than motor/trans. My guess is not much so sounds like I may have another winter project.
> 
> Thanks.


It's actually a bit of an enjoyable job if you have the right tools. If you hear any whining, don't wait!!! If you let bad bearings go too long, you can loose and axle while driving, and they're like brakes... They cost $100 to fix when they start making noise, and you can tack a few hundred bucks on to that, every week that you wait!

No one can say what shape yours are in, but if you were near water or theyre original, at least check them.


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