Drum brakes were a design that started way back when automobiles were just coming around. Times have changed, but drums are still a cheap, lightweight option, so they can still be found on the back of brand new vehicles. Back in the day, drums worked just fine when life was a bit slower and everyone else was stopping on drums. Somewhere in the mid-'60s, the car manufacturers figured out the disc brake design was far superior and by the '70s pretty much all cars were fitted with disc brakes up front. Then brakes started to get smarter with the advent of anti-lock technology. Now the roads are littered with all kinds of cars that can stop way better than any drum brake-equipped muscle car.
A set of drum brakes in good working order will stop a car, but in a longer distance than disc brakes, plus they are temperamental, susceptible to pulling and fade (especially when wet), and high maintenance compared to discs. Drums require periotic adjustment, and have a lot more moving parts to fail as well. Discs are much simpler, way easier to maintain and typically need no attention until it's time to change the pads. On top of all this, disc brakes will stop better than drums on the first stop till the last because by design they dissipate heat better.
So, unless you are performing a numbers-matching stock restoration-type build there is no real reason except budgetary concerns for not swapping to discs. If your budget is super tight, then maybe discs are out of your reach, but let us put it in perspective for you. Unless all your drum stuff is in good shape you are going to need to rebuild them that could cost you up to $300 to do it right. That coin could be applied to a conversion instead. We found a complete front disc conversion and everything else we needed from Classic Performance Products (CPP) that set us back $959. It's built with all new components and includes everything from the spindles and bearings, all the way to the rubber lines. If you factor in what the drum rebuild would cost anyway, it starts to make a lot more sense to convert. The car will be safer, easier to maintain, and stop a lot better—possibly saving your front clip from parking itself into the back of the vehicle in front of you. This is a big consideration, especially in these days of distracted driving and 80 mph (and up) highway speeds.
We went over to D&P Classic Chevy in Huntington Beach, California, to follow along as the shop converted a manual four-wheel-drum '68 Camaro to power front disc brakes. The job was done in one day with no exotic tools and other than bleeding, the system was installed by one person.
|Part numbers and prices|
|6769CBK-S11-2||Complete disc brake kit with stock 11-inch booster $799.00|
|6774SP-A||Stock spindle steer arm set $69.00|
|VHK1-25||Vacuum hose kit 90-degree fitting and 25 inches of hose $12.00|
|6769LK-OM||Front &r ear disc brake conversion line kit, OEM steel $79.00|