Replace Your Drums With Discs

   Classic Performance Products 

 Replace Your Drums With Discs 

Then Add A Drop.

Upgrade you '67-'70 Chevy/GMC Suspension


Customizing an early model pickup can entail thousands of different options, all of which suit our needs or cosmetic desires. Generally though, the mission of  personalization revolves around upgrading along with the addition of Luxury.  On the '67-70 Chevy and GMC pickups, there is one enhancing option that most people fail to take into consideration or don't have the resources or guidance to accomplish. This task I'm speaking of is the conversion from front drum brakes to disc brakes using OEM products. Many enthusiasts desire the option of disc brakes over drums, mainly for improved stopping performance, but also because this conversion will allow them to install dropped spindles and other bolt-on lowering products. Let's face it, front drum brakes on the  '67-70 Chevy trucks limits our personalizing options. 
By converting to disc brakes, you have a better selection of wheels to choose from, a larger selection of suspension modifications, and improved performance with power brakes being a big bonus. The power brake portion of the installation uses all OEM components and some trick new brackets to really make this installation successful and complete. Until lately, it was difficult to tackle this job because no one had a kit available that would make the installation easy. Classic Performance Products, suppliers of a variety of classic Chevy and GMC components, have recently assembled a kit that allows enthusiasts to convert their '67-70 pickups over to power disc brakes while also creating the option for incorporating dropped spindles and short coil springs to lower the front suspension to a road hugging height. 


















In addition to simply adding disc brakes and a lowering kit to the front of your truck, YOU must remember that your wheel bolt pattern will now be five-lug instead of the original truck type six-lug pattern. You can either re-drill the rear axle plates of the truck to the five-on-five lug pattern, install a matching rear end  with the same five-lug pattern or do what we did in this case which was to call Wheel Vintique and ordered a set of traditional rally wheels with the trick beauty rings and center caps for a clean look. The wheels were ordered with a five-lug pattern up front and the original stock pattern in the rear so that the project wouldn't get to expensive.  Remember, you are converting your brake system over to disc in the front and are maintaining drums in the rear.  A power brake assembly conversion such as what we will show you should be considered. All of the parts you would need are OEM. In fact any assembly from '71-'83 can be installed depending upon your resources.


1.  To make the installation a little easier, we removed the front sheet metal but you don't have to. To begin, loosen (but do not remove) the stock ball joint nuts holding the spindle on. You will probably have to use a fork bar to get the spindle loose. For safety, release the coil pressure by keeping a jack under the lower control arm, using the truck's weight to hold the spring in place. Warning! you can injured if this isn't done right.
2.  Now the original spindle and brake assembly can be removed.
3.  Let the jack down slowly to release the original coil spring.
4.  If your truck has the original lower ball joints, you will probably have to use a hammer to remove them.
5.  Now press the new ball joints which are a '73-'80 version into the lower control arm.
6.  The upper ball joint is attached with factory rivets and requires an air chisel or comparable tool to remove.
7.  After the old ball joint is removed, install the new version. The nuts and bolts are provided in the kit.
8. The lowered coil spring can now be installed between the control arms. It just so happens that we had a set of what we call welfare springs. That means that the owner of the truck that these springs came out of was too cheap to lower his truck the right way so he used a torch to heat the springs. This is the result. Folks, don't even think about it! Get yourself some lowered coil springs.


9.  You will have to rely on the floor jack once again to press the coil spring together so that the new dropped spindle can be installed. Make sure that the coil spring is set properly into the control arm before you continue.
10.   After you bolt the new spindle on, insert the cotter pins and be sure to bend one end over the nut so that the nut will have no chance of backing off.
11. Since you are going have disc brakes, it is advisable to install dust shields. The kit doesn't provide them but you can get them from any GM parts stores. The GM part numbers are 14054937 for the left and 14054938 for the right.
12.  Now you can grease-up the wheel bearings and install them into the rotor.
13.  Install the new rotor and the outer bearings with plenty of grease.
14. Use the original nut and washer from the old spindle, which matches the bearing and axle, to tighten down the rotor. A cotter pin should be installed here as well.


15.  A hammer will be needed to install the bearing cover. It is important that you don't forget to put the cover on because any dirt or metal shavings can severely damage the bearings.
16.  Now the calipers can be bolted-up. Installation of the brake calipers requires an allen wrench.
17.  To attach the new brake line to the caliper, be sure that there is a copper washer on both sides of the fitting. In same instances, the fitting may have to be bent slightly to clear the spindle.
18.  The brake fluid hose bracket that attaches to the spindle should be trimmed for a perfect fit.
19.  A cutting wheel works best to trim the edges off.
20.  When enough excess is trimmed-off, bolt the bracket to the spindle.
21.  Here is where you must pay close attention to the instructions. The kit provides a new outer tie-rod end and custom made sleeve. The old outer tie-rod end will now become the inner tie-rod end if it is still useable.


22.  Because of the positioning of the old outer tie-rod end when placed on the inside, the kit provides a 90 degree zerk fitting to make lubing access much easier. 
23. Use the new tie-rod end sleeve provided in the kit and install as pictured. 
24.   Both of the tie-rod ends require joint sleeves to retain the lubing grease. 
25. When the tie-rod assembly is complete, it can be installed with cotter pins to secure the nuts. 
26.  Be sure to lube-up all of the joint areas of the suspension before you take off down the road. Both of the ball joints and tie-rod ends require grease. 
27.  The kit doesn't include them but it is advisable to install new shocks. In this case, a gas-magnum version is used.


28. There you have it, disc brakes, and a lowered suspension. The suspension is actually lowered about 3 1/2 inches from stock.  Now head to an alignment shop to insure proper tire wear and tracking.
29.  To lower the rear suspension to meet the new lowered height of the front, a set of  C.P.P lowered coil springs are installed in place of the stockers. You can see the difference which is measureable to a four-inch drop.
30. If you chose to ditch the stock six-lug rear end to go with a five-lug rear end, a 1971 or '72  half-ton truck will provide you with a good donor rear end.
31.  It is important that you consider installing a power brake booster, master cylinder and proportioning valve.  A '73-80 version bolts-up nicely as does a '71-72 version. The only difference is that the '71-72 version requires a slightly longer thrust rod. This is Classic Performance Products' new power brake kit that comes complete with everything  you need to complete the conversion. Trust me, this setup will stop your truck very effectively! 
32.  The 1967-'70 truck fans will recognize this; it's the manual brake master cylinder from the stock brake system. After this truck was converted to disc brakes, we opted to convert the system over to power.
33.  The manual master cylinder is attached only to the lower two bulkhead studs. Remove the master cylinder and the nuts attached to the upper bulkhead studs.
34. Slide the thrust rod through the firewall and attach the power booster bracket to the bulkhead studs.
35.  At this point, you should have the power booster firmly mounted to the firewall in preparation for the master cylinder to be installed. 


36. Making sure that the pressure pin is still inside the power booster (it likes to fall out if you're not careful), the new power master cylinder can be installed.
37.  The new proportioning valve comes completely assembled with required hardlines, fittings and installation bracket assembled. The mounting bracket simply slides onto the booster stud between the booster and the master cylinder.
38.  The hardlines have been pre-bent to precisely fit the master cylinder parts. Make sure that the fittings are good and tight. 
39.  There is a "T" fitting on the cross member that allows the brake lines from the proportioning valve to connect with the front and rear lines. You will probably have to replace the stock lines to the "T" fitting with new hardlines that you can bend up, or with a braided steel kit that Classic Performance Products has.
40.  You will also need to locate a vacuum source somewhere on your engine. Many carburetors have vacuum ports on their base plates or you may want to plumb your intake with a multi-port fitting.
41.  This is what the power brake assembly looked like from the factory in 1972. You will notice that there is a support bracket extending from the power booster bracket over to the firewall. Now, the 1971 and '72 firewall designs are different from 1967-'70. The fuse block, parking brake and speedometer cable are located in different places.
42. This diagram shows you how to drill the bracket hole precisely where you will need to for the 1967-'70 Chevy trucks.  Looking from the inside at the firewall, measure over five inches from the pad fastener closest to the steering column, then measure upwards three inches and drill.
43. The support bracket can now be attached as shown. If you have drilled the hole properly, it should be no problem mounting the bracket.

Classic Performance Products  378 E Orangethorpe Ave.,  Placentia CA 92870  Tech Line 714-522-2000


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