One of the most popular classic trucks are the 1967-72 Chevy and GMC pickups. GM produced more light-duty pickups during this era than any generation before it which means there are still a lot of them out there for consumers who are looking to restore or customize one. But like any classic truck, many engineering features such as suspension design could do with some much needed upgrading. This is particularly important for the truck owner who wants to lower his truck along with increasing the performance and handling.
One of the very first endeavors that Classic Performance Products sought was the development of a complete suspension upgrade kit for the '67-72 GM pickups. Over the years CPP has fine tuned their Grand Slam Kit into a true, complete conversion package that provides the consumer with geometrically correct suspension lowering components as well as a full power brake system complete with front disc brake rotors!
There were many different suspension and brake options spanning this era. Whether or not the Grand Slam is right for your truck will depend on your current set up, not to mention what you want it to be like when you are finished. Those with '67-70 model trucks are the ones who can take full advantage of the Grand Slam kit which not only provides the owner with the ability to correctly lower his truck, but also incorporates the upgrading to power disc brakes in either 5 or 6 lug bolt patterns.
This kit includes 2.5-inch dropped front spindles, bearings, calipers, 12-inch rotors, brake hoses, master cylinder, power booster, prop-valve, four gas shocks, four lowered coil springs, inner and outer tie rod ends, custom adjusting sleeves, upper and lower ball joints, seals, spindle nuts, dust shields and dust caps. All necessary hardware is included. The amount of drop can be determined at the time of purchase as different height front and rear coil springs are available. Some factory drum brake wheels may not work with the new bolt pattern or studs. Factory 6-lug applications had 7/16-inch studs and 5 on 5-lug kits have ½-inch studs. If your truck has leaf springs, please inquire as to your lowering options.
The following is a step-by-step guide to installing the complete CPP Grand Slam Kit on a 1969 Chevy truck in original condition.
CLA SSIC PERFORMANCE PRODUCTS, INC.
175 E. FREEDOM AVE., DEPT TEN
ANAHEIM, CA 92801
(714) 522-2000
 |  Step one is to make sure the truck is secured on a lift or quality stands before removing the wheels. As you will note, this truck is a six-lug pattern with manual drum brakes. The six lug will be converted to five lug which also means the wheels will have to be changed. Six lug rotors are available should the owner would want to retain the original wheels. |  Remove the outer tie rod end nut. |
 To loosen the bite of over 25 years of use, a hammer is used to strike the knuckle where the tie rod connects. |  Remove the tie rod from the steering knuckle. |  Loosen the lower ball joint nut. Do not remove. |
 Loosen the upper ball joint nut. Do not remove. |  Remove the shock and upper shock mount. |  Remove the retainer clip that connects the flexible brake hose to the hard line. |
 With both ball joint nuts still loosely attached, tap the spindle at the ball joint points with a hammer to force the ball joints to loosen up from the knuckle points. |  A stand is placed under the lower control arm to support the suspension so the spindle assembly can be safely removed. Do not attempt to remove the spindle assembly without supporting the lower control arm. The coil spring is still under tension and could come flying out causing injury. |  Lift the upper control arm up to remove the ball joint from the spindle. The entire spindle assembly can then be removed. |
 Lower control arm is lowered and the coil spring removed. |  Place a sturdy stand under the lower control arm, one that is strong enough to handle the force of knocking out the lower ball joint. |  The lower ball joint won't come out easily, but it will come out. These will be replaced with new ball joints with a correct stem taper to match the new spindles. |
 Place the new ball joint into a ball joint press from the bottom. If you do not have a ball joint press, seek the services of a machine shop to have it properly pressed in. |  An impact wrench is used to apply enough force to fully seat the ball joint. |  Here is the new lower ball joint properly installed into the control arm. |
 Install the ball joint grease seal. |  An air chisel is required to knock out the four rivets holding the original upper ball joint in place. |  Remove the upper ball joint from the control arm. |
 An air sander is used to clean up the surface where the new ball joint will be installed. |  Install the new upper ball joint into the upper control arm. |  Install the provided hardware as shown, bolt through the bottom and nuts on top. |
 Permanently tighten the ball joint hardware. |  In the case of this truck, the original frame shock mount was very rusted so a new shock mount available from CPP was installed. |  Install the new shock onto the upper mount. |
 On flaw the factory mount system had was that if the driver was aggressive with his navigation, the frame could buckle at the upper mounting point. The solution was to design a shock mount support bracket which attaches to the shock mount and to the frame. |  Two half inch holes must be drilled into the frame. The holes are started with a smaller 3/8-inch bit. |  A half-inch bit is then used to make the appropriate sized holes for the mounting hardware. |
 Here is the completed installation of the upper shock mount and support bracket. |  This comparison shows the difference between the new lower coil spring (left) and the factory spring (right). While the dropped spindle produces two inches of drop, the kit also includes lowered coils springs designed to increase the desired amount lowering while enhancing the ride qualities. The lowered coils springs are available from 1-3 inches of drop. We used a three-inch drop spring for this installation. |  Using a jack or hydraulic jack stand, the new coil spring is placed into the frame pocket and lower control arm pocket while the lower control arm is pressed upwards. |
 Install the shock to the lower control arm which will hold the lower control arm in place. |  The spindle and brakes can be ordered pre-assembled or as separate components. For those who will do the assembly themselves, the following steps illustrate procedure. The first step is to use the provided bolts to attach the new dust shield to the spindle. |  The new 12-inch rotors come packaged with oil on the rotor surface to prevent premature rusting. Use a degreaser such as carb or brake cleaner to remove the oil from the rotors. |
 The new bearings must be packed with high-temperature grease prior to installing them into the hubs. |  You don't want to have to re-grease your bearing later, so make sure and get them packed full the first time. |  Install the rear bearing into the brake rotor hub. |
 Install the provided new rear bearing seal. |  The rear seal must be pressed on. A flat piece of steel and a rubber hand mallet is enough to press the seal on tight. |  Place the rotor onto the spindle. |
 Install the front bearings. |  Place the spindle nut washer over the bearing. |  Install the provided 1-1/16-inch castle nut. |
 Hand tighten the nut. Be sure not to over-tighten it! Get it good and snug, then back off a small amount. |  Install a cotter pin through the castle nut and spindle to lock the nut in place. Trim off the excess so the dust cap will fit. |  Place the new dust cap over the hub and lightly tap it to press it into the hub. |
 |  The new disc brake calipers come with the pads installed. Make sure the piston is fully compressed into the housing before trying to install onto the rotors. You can add some anti-squeak lubricant to the backing plates of the pads should you choose to. |  Carefully install the calipers onto the rotors. Make sure the bleed valve is point upwards and not downwards. |
 Secure the caliper with the provided caliper bolts. |  Attach and secure the provided new brake line to the caliper. Be sure to use the copper washer when attaching the fitting! |  With the lower control arm supported, the spindle and brake assembly is placed on the lower ball joint first, followed by attaching lowering the upper control arm down to insert the upper ball joint into the upper spindle ball joint knuckle. |
 |  Install the provided castle nuts and tighten. |  Insert cotter pins through both upper and lower ball joint nuts. Trim the excess of one side of the pin while folding the other over the top of the spindle. |
 Attach the flexible brake line to the frame mounted hard line connection. |  Install the flat locking pin to complete the connection of the brake line. |  Remove the entire tie rod from the drag link. A good tip is to measure the length from outer rod end to inner rod end so that you can create the same length when the new tie rods are assembled. This will get the alignment in the ballpark before taking the truck to have it aligned. |
 Screw the tie rods into the custom made billet aluminum adjuster sleeve. One turns left and one turns right. |  Attach the outer tie rod to the steering knuckle. |  Attach the inner tie rod to the drag link. |
 Install the provided castle nuts, tighten and secure with a cotter pin. |  |  |
 As with any grease-able joint of suspension modification, be sure to grease the ball joints and tie rod ends. |  REAR--First step in the rear is to remove the shocks. |  Remove the lower spring bolt from the trailing arm. |
 Unbolt the top of the spring from the frame. Remove the spring. Retain the spring mounting cups as they will be reused when installing the new spring. |  Like the front, there are different spring heights available depending on what level the consumer wants his truck to sit. The new springs are shorter and thinner to greatly enhance the ride. |  Install the spring over the control arm and up against the frame. (note: We also installed CPP Tubular Trailing Arms which are direct replacement for the factory trailing arms and are sold separately.) |
 The spring bolt and retention cup are positioned to be tightened. |  Tighten the upper spring bolt and nut. |  Position the spring and retention cup then tighten the lower spring bolt and nut. |
 Install the new, shorter shock absorbers, top mount first. |  Depending on how short your new spring is, the shock may not be able to reach the lower shock mount with the suspension at full droop. The lower shock mount can be attached when the truck is back on the ground. |  POWER BRAKE ASSEMBLY-- The first step is to begin removal of the factory brake lines from the prop-valve. |
 |  Remove the brake system indicator wire from the sender in the prop-valve. |  Remove the rear brake line from the prop-valve. |
 Unbolt the master cylinder from the firewall. If your truck has a power booster, unbolt the bracket from the firewall. |  Once the nuts are removed from the firewall studs, remove the master cylinder. |  With the assembly removed you should see four studs and the brake push rod sticking through the firewall. |
 The new CPP Power Brake Booster Kit utilizes one of the bolt holes that secures the steering column, found just under the lower driver's side firewall stud. This bolt needs to be removed so that it can be used as a fifth mounting point for the booster bracket. |  Remove the brake pedal clevis from the brake pedal arm inside the truck and pull the brake push rod out. |  Remove the clevis from the factory brake push rod. |
 Install the factory clevis onto the new push rod attached to the power booster assembly. The proper position of the clevis will be determined later when attaching to the brake pedal. |  Install the new rubber firewall seal onto the push rod. |  Install the power booster assembly onto the four firewall studs while inserting the push rod through the center hole. |
 |  A 9/16 wrench is used to tighten the four nuts onto the studs, permanently securing the bracket. |  |
 The bolt removed from the steering column bracket is installed through the bracket and into its original hole. This will complete the installation of the booster assembly to the firewall. |  From under the dash, connect the push rod clevis to the brake pedal. Adjust the clevis on the push rod so the brake pedal is as high as possible without preloading the brake booster and the brake lights are off. |  A new brake sensor wire needs to be spliced to the old wire to make it long enough to reach the prop-valve. Cut the old wire, leaving plenty of room to work. |
 |  Crimp the new wire lead with the existing wire. |  Remove the frame clamp that secures the brake lines. |
 Pre '71 drum brake trucks will need to modify the existing lines and use brake fitting adapters. If you are not familiar with how to cut and manufacture new brake lines, seek a professional to have them cut and bent for you. Properly bends and fitting seating is very important for the performance of your brake system. Here we begin with a tube cutter to cut the line approximately half way up the vertical rise of the line. |  A new fitting is placed onto the line before the new line flare is created. |  A flaring tool is used to create the need flare in the line. |
 At the prop-valve, measure the desired distance before the necessary bend towards the cut rear line. |  Double check your desired length to be sure the brake line will be straight at the fitting, yet bend with enough clearance to avoid the booster. |  The pre fabricated new brake line is inserted into a hand line bender. Before proceeding, double check the measurement. |
 You will want the first bend to be 90 degrees to allow the line to lead straight over to the old cut line. |  Here we used two 90-degree bends to get the line over to the old line. Mark the final bend starting point for the line to meet the old brake line about one inch from the vertical intersection point of the two lines. |  |
 Make the final 90-degree bend. |  Mark the cutting point on the new line. Make this mark approximately ¾-inch up from the cut on the old line to compensate for the length of the union fitting that will be used to connect the two lines. |  Install the line fitting then make the final cut and flare to the new line. |
 Attach the new rear line to the prop valve. |  Install a union fitting onto the new rear line fitting. |  Attach the fitting on the old line to the union fitting. |
 Repeat the steps on the rear line for the front line by cutting the front line at roughly the same location as the rear line. |  Install the line fitting then flare the line. |  Like the new rear brake line, the front line starts with a 90-degree bend and then is angled approximately 45-degrees from the prop-valve over to the old front brake line so the bend point to the line can be marked. |
 Install a line fitting, flare the line then install both the new line fitting and old line with new fitting into a union. |  Specifically using line wrenches, tighten the new fittings to the prop-valve. |  |
 Permanently tighten the line fittings to the unions installed where the new and old lines meet. |  |  Before proceeding any further, use the line wrenches to check all of the master cylinder and prop-valve fittings. |
 Remove the master cylinder cover and place in a clean location so as to not get any debris on the cover gasket. |  Pour DOT 3 brake fluid into both the front and rear master cylinder reservoirs. |  Fill to approximately 3/8-inch from the top. |
 CPP recommends bench bleeding your master cylinder prior to installation. Since many consumers are not familiar with how to bench bleed a master cylinder, here is an alternative and equally successful method. Locate a syringe with a small tip, or a larger syringe with a rubber tip and small hole. |  You will notice two small holes in each reservoir. The rear holes in each reservoir serve the fluid into the master cylinder and brake lines. The front holes are where the pressure comes from that pushes the fluid through the master cylinder and into the lines. Insert the syringe tip into the brake fluid and extract fluid to fill the syringe. |  Place the tip into the rear holes and press the fluid slowly through. |
 You should see small bubbles rise up if you are doing it correctly. Repeat the process until there are not bubbles, only fluid rising through the front hole which will be visible at the surface of the fluid. |  Top the master cylinder off with fluid before continuing. |  There are various ways to bleed. See the brake bleeding guide or visit the "How To Bleed Brakes" on the CPP web site for more information. Here we attach a vacuum bleeder onto the passenger side rear brake caliper bleeder valve to provide suction while using the previously illustrated method of bleeding the master cylinder. |
 Once each line has been effectively bled and you are confident there is no air in the line, the master cylinder is topped off again and the master cylinder cover installed. |  Power boosters require vacuum to operate. Locate a vacuum source on the intake manifold. |  Install a threaded fitting into the vacuum source and attached a vacuum rated hose onto the fitting. |
 Attach the vacuum hose to the vacuum fitting on the power booster. (note: If the engine cannot produce at least 18-inches of vacuum then a vacuum pump may be needed in order for the booster to function properly.) |  Here is the finished installation of the CPP Power Brake Booster Kit. |  This is roughly the what the new height of your truck will be. The amount of suspension lowering for this truck was 5 inches. |
