# Drum to disc conversion



## Mike E (Jun 9, 2018)

Hello, I bought a 68 GTO Convertible, numbers matching. I'm not happy with the power drum brakes on the car at all. Two questions....first, will a drum to disc conversion lower the value? Just wondering if this ruins the originality of the vehicle. Second, should I just get the front brakes converted? Im told that a rear conversion wont make much difference and will definitely be less expensive. I appreciate all of your thoughts. Thanks!


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## ajluzi1957 (Mar 22, 2017)

Hi Mike,
there are many more experts on here than me, but i purchased a 69 convertible with drum brakes that were just horrible... I converted over to front discs and it was very easy and the results were fantastic. I personally would not do the rear ones.

As far as value, I saved all the components that I removed, so if I do sell the car and the buyer wants the original parts, he/she can have them and it would be an easy conversion back if they desired.

Armand


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## cij911 (Oct 25, 2017)

^^ Ditto.....I would advocate for the rear swap as well, but more for looks....unless of course you drive it like you stole it then maybe you'll get some slight performance improvement with rear discs (front do ~80% of the work).


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## Mike E (Jun 9, 2018)

Thanks guys. Much appreciated. Yes, I plan on keeping the drum components as well in case the next possible owner would ever want to revert.


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## Nicholas (Jan 16, 2017)

Mike E, what is it ur hoping to gain by converting to disc?? I have power disc on the front of my '71, because it came with it. If it had power drums, I would have left it alone. I have power drums on my '62 SS 409, and they work just fine. On my '67 GTO, I had power drum brakes and they also worked just fine. I've changed them out on my '56 and '57 Chevys, no real regret, but I wouldn't do it again. I'm going out on a limb here, but I've never read anything conclusive about disc stopping you better then drums. Sure, disc are better on freeways, bumper to bumper traffic, they don't fade like drums do with constant use, but how many of us travel that way. I find nothing wrong with power drum brakes that are adjusted properly and working as they should. Just my opinion and experience.


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## cij911 (Oct 25, 2017)

Nicholas said:


> Mike E, what is it ur hoping to gain by converting to disc?? I have power disc on the front of my '71, because it came with it. If it had power drums, I would have left it alone. I have power drums on my '62 SS 409, and they work just fine. On my '67 GTO, I had power drum brakes and they also worked just fine. I've changed them out on my '56 and '57 Chevys, no real regret, but I wouldn't do it again. I'm going out on a limb here, but I've never read anything conclusive about disc stopping you better then drums. Sure, disc are better on freeways, bumper to bumper traffic, they don't fade like drums do with constant use, but how many of us travel that way. I find nothing wrong with power drum brakes that are adjusted properly and working as they should. Just my opinion and experience.


Well with all do respect if you have a 400 hp + car, I sure as hope you would want and appreciate great brakes. Drum brakes are absolutely awful in comparison to disc - distant, water, fade, and feel. If you drive your GTO like a prized show car and barely go above 35mph, then drum brakes will probably suffice.


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## Mike E (Jun 9, 2018)

I like to drive my GTO, and periodically press the pedal and enjoy that beautiful thrust. I had my drums replaced with newer drums and even after adjusting, I find it difficult to stop quickly, I feel thigh fatigue after having to tend to it on your plus rides, an notice an uneven brake, meaning that it sort of hops to a stop. Plus, my driveway is a slight incline into my garage. When I reverse out for a drive, I find a lot of trouble even getting the car to stop before I'm at the end of my driveway. If discs are less effort to use, and stop better, if be for that. Plus I could keep the new drum hardware if someone wants to revert.


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## Shake-N-Bake (Jun 16, 2015)

Mike E said:


> Hello, I bought a 68 GTO Convertible, numbers matching. I'm not happy with the power drum brakes on the car at all. Two questions....first, will a drum to disc conversion lower the value? Just wondering if this ruins the originality of the vehicle. Second, should I just get the front brakes converted? Im told that a rear conversion wont make much difference and will definitely be less expensive. I appreciate all of your thoughts. Thanks!


Really won't hurt the value by converting to disk brakes. Your car won't be numbers matching any longer but if you keep the original parts then it all can be reversed later if needed. It's your car, enjoy it. If having more confidence in the brakes will allow you to drive it more often then it's a no brainer. If you just want to show the car then that would be a different story.

Just do the fronts and see how you like it. If you want more stopping power then do the rears. There are some good write ups on rear disk brake conversions using parts commonly sourced from salvage yards.

Sent from my SM-G930V using Tapatalk


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## Pinion head (Jan 3, 2015)

Been down this road so many times. Have personally converted nearly two dozen A-body's and '67-69 F-body's to factory disc brakes using '69 single piston calipers/ factory caliper brackets & factory disc spindles. Have also sold a ton of nice original disc spindles/caliper brackets/rebuilt calipers/hose brackets, & original prop valves to restorers as well as the local "smash em up" daily driver crowd. 

Time after time, the front disc swap was because the customer wanted it, thought he "had to have it" on order to safely drive the car.In so many cases, agree with Nicholas, an upgraded drum system would have worked extremely well, and having gone both routes, the expense would have been considerably less than converting to a quality factory front disc set-up. In several cases, have actually removed converted front disc brake systems and put the car back to factory 4 wheel drum. One of my own keepers has received the conversion back to 4 wheel drum after receiving a truly Concours factory disc changeover (rebuilt correct dated calipers, replated correct dated part # caliper brackets, rebuilt correct casting master cYL, Gregori restored correct dates booster). Simply put, the highly detailed early '71 production factory disc setup added nothing stopping wise over a well prepped high matrix composition brake shoe drum setup. What did it add, about 50 lbs to the front of the T-37. With the Gregori restored booster, it also looked "real pretty" under the hood. There are many of us that are strong believers in the upgraded brake shoes and stiffer return springs offered by MusclecarBrakes.com (previous Praise Dyno Brakes). Link to earlier discussion:

http://www.gtoforum.com/f154/ultimate-drum-brake-parts-94073/

A problem with the aftermarket '69 style single piston caliper front disc changeovers over the last 15+ years has been what I'll refer to as the "Race to the Bottom" as far price goes while sacrificing considerable QUALITY of component parts To put it in simple to understand words:
-$79 for a PAIR of repro disc spindles, what is one getting? Time and time again, the cheap Chinese disc spindles have proved to be JUNK. Originally poorly machined on the bolt holes for steering arms, then run after run of the wrong taper holes for the ball joint studs to go through. wow! So many examples of these junk disc spindles sheering off ballpoint studs. There is no way that kind of offshore cheap [email protected] is going on any vehicle that I'm working on, or any vehicle that any of my friends vehicles who have been asking my input/parts.
-Poorly die stamped caliper brackets that have to be tweaked and ground on to fit = more poor quality JUNK.
-8" diam aftermarket boosters that don't have the vac capacity to work... more Junk! 

Newsflash! If purchasing a front "disc brake conversion" complete with cheap disc spindles from one of the big internet sellers on price alone, the above parts are what you are getting. There are better parts out there, got to have a factory style front disc set-up, there are better ways to go w/o compromising integrity of some very important suspension pieces.


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## Nicholas (Jan 16, 2017)

Mike E said:


> I like to drive my GTO, and periodically press the pedal and enjoy that beautiful thrust. I had my drums replaced with newer drums and even after adjusting, I find it difficult to stop quickly, I feel thigh fatigue after having to tend to it on your plus rides, an notice an uneven brake, meaning that it sort of hops to a stop. Plus, my driveway is a slight incline into my garage. When I reverse out for a drive, I find a lot of trouble even getting the car to stop before I'm at the end of my driveway. If discs are less effort to use, and stop better, if be for that. Plus I could keep the new drum hardware if someone wants to revert.


I understand and respect your position. I was just sharing my limited experience and opinion. I like the power drum on my '62 409. Very adequate. No desire to change anything. At times, I do get that car at higher speeds and have never had a problem slowing it down. My '71 GTO has factory power disc up front and they work fine also, as long as there is enough vacuum, but that's not the brakes fault. I wouldn't change them to drum. What it comes down to, is what you feel comfortable and confident with. Your car. You're driving it. Best wishes.


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## cij911 (Oct 25, 2017)

FWIW - I am installing corvette 98-02 discs on my GTO, and this is almost entirely "bolt on", which should provide great braking.


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## 11th Indian (Feb 15, 2018)

C5 brakes? sounds good.... 

Interesting topic. I have 4 wheel manual drums on my 72. It amazing what we get used to. They seem quite adequate and just require a lot of pedal pressure. Cycling a few thousand miles a year has prepared my legs, and after a few minutes its old hat. 

I just never ever follow too closely…..


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## PontiacJim (Dec 29, 2012)

I have found that the shoe material makes a difference. If you get the "Premium" or "Life Guarantee" types, they are very hard and typically semi-metallic. These stop very poor as it take a lot of heat to get them to work and a panic stop won't cut it and then its too late. Might work better on smaller rotors/drums that rotate faster due to their smaller diameter and heat up quicker.

I have always selected the cheapest line of shoe or disc pad. They are softer and grab much better. They may wear just a little sooner, BUT, they wont' eat up your drums/discs as fast a the Premium material does - and thus the life time guarantee as the pads/shoes are really cheap, but then you have to buy new drums/discs and that's where they make money.

A disc brake conversion is a plus and won't hurt value - especially when you can stop "right now" versus rear-ending another car which will most certainly hurt the value more.

Save the original parts and store them. You do not need discs on the rear as the front's do most of the braking. Get a complete change over to include the correct master cylinder and proportioning valve. You don't need slotted/drilled rotors unless you just want to add them for bragging rights. Typically you need to get the correct spindles to match the disc brake swap, but I believe some kits are a bolt-on using the existing spindles.

Rim clearance may also be an issue - you need rims made for the disc brakes.


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## Shake-N-Bake (Jun 16, 2015)

Nicholas said:


> I understand and respect your position. I was just sharing my limited experience and opinion. I like the power drum on my '62 409. Very adequate. No desire to change anything. At times, I do get that car at higher speeds and have never had a problem slowing it down. My '71 GTO has factory power disc up front and they work fine also, as long as there is enough vacuum, but that's not the brakes fault. I wouldn't change them to drum. What it comes down to, is what you feel comfortable and confident with. Your car. You're driving it. Best wishes.


Interesting point you make about then '62. Those drums are quite effective...I noticed that on our '61 348 Bel Air bubble top and it just has manual drums. However, that car stops very well.....MUCH better than my '55 Bel Air does. No desire to upgrade brakes on the '61 but am thinking about it for the '55. Just hate to deviate much from stock....I am one of those that enjoys the mechanicals as how it left the factory. We each have our preferences with these things.


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## Nicholas (Jan 16, 2017)

Shake-N-Bake said:


> Interesting point you make about then '62. Those drums are quite effective...I noticed that on our '61 348 Bel Air bubble top and it just has manual drums. However, that car stops very well.....MUCH better than my '55 Bel Air does. No desire to upgrade brakes on the '61 but am thinking about it for the '55. Just hate to deviate much from stock....I am one of those that enjoys the mechanicals as how it left the factory. We each have our preferences with these things.


When I first got my '62, I installed all new lines, MC, brake shoes, and whatever new parts were still available for the brakes. Sent the booster to "Booster Dewey" for a rebuild. My power drum brakes work perfectly. Tracks straight when the brakes are applied. Guess they are like anything mechanical. Have to use quality parts and have everything adjusted properly.


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