Classic Performance Products 378 E Orangethorpe Ave., Placentia CA 92870

Classic Performance Products

1963-72 Chevy Truck Tubular Suspension Install

By Bob Ryder
Classic Performance Products in Anaheim, California, was established in 1991 by Jim Ries and has been an innovator in manufacturing classic truck and automotive custom suspension components, both hard suspension parts and pneumatic bag systems. CPP also specializes in disc brake conversions, master cylinders, power boosters, custom aluminum gas tanks, and power steering units, tilt steering columns, and other cool custom stuff.
Part I:
This will be the first of three suspension upgrade tech install articles for '63-72 Chevy trucks. Part I will consist of installing a CPP rear suspension with a redesigned "flat" center crossmember with an optional driveshaft support bearing. All crossmem- bers come with larger 4x5-inch exhaust openings. The rear trailing arm mounts have been relocated 4 inches up to achieve the correct pinion angle. A pair of beefy, 2-inch DOM tubular trailing arms will replace the wimpy stock units. The tubular trailing arm bushings are made of a newly patented, D-Spec, heat-resistant, self-lubricating material that offers long life and an amazingly quiet, comfortable ride. A pair of shorter progressive coil springs and CPP gas-filled shocks allow another 2 inches of drop in the rear ride height. To eliminate any lateral movement of the rearend housing, a CPP track bar will be installed. All this will allow the rear suspension to sit 6 inches lower than the stock ride height.
Part II:
Here we will feature the installation of Classic Performance Products' front suspension, consisting of tubular upper and lower control arms with a pair of 2-inch drop spindles and shorter coil springs, allowing the nose to be dropped 4 inches.
Part III:
The third tech article will upgrade the original drum brakes to a much more efficient CPP front and rear disc brake system with E-brake. The kit features large rotors and dual-piston calipers at all four corners. We will be capturing all the critical moves as fabricator/installation technician Jeff Wise and engineer/designer Danny Nix flex their talents and skills as they install the CPP tubular rear suspension kit.

1...A newly designed 1/4-inch-thick, laser-cut, steel plate, dropped center crossmember features a larger driveshalt opening (also available with a driveshalt support bearing). larger 4x5-inch oval exhaust openings relocate the trailing arm pickup points up 4 inches and correct the factory pinion angle. The crossmember main plate's notched sides allow clearance space for the brake line, fuel line, and large diameter air lines. There are also new 1-inch-diameter tubular trailing arms with a coil spring mounting pad.

2...The remainder of the CPP rear suspension C-notch 6-inch drop kit includes replacement U-bolts, 2-inch lowering blocks, 4-inch shorter coil springs, shock remounting brackets, CPP shocks, and a pair offramerail C-notch reinforcing plates.

3-4...The well-worn shocks were unbolted and removed from the framerails and original trailing arms.

5...To separate the rear axle housing from the rear trailing arms, an air impact gun is used to remove the U-bolt nuts.

6...The original '72 rear suspension track bar was unbolted from the factory rear axle housing; notice the rear axle-housing track bar mounting bar built into the axle housing. With the CPP track bar, it will bolt up to the right rear tubular trailing arm and left framerail.

7...With all the securing fasteners removed, the rear end axle housing was removed from the factory trailing arms and frame.

8-9...A cheater bar was used to remove the rusty old bolts from the coil spring framerail mount. The rear factory coil spring was removed from the framerail mount.

10-11...An ol' skool cutting torch was used to blaze off the factory rear bump stop mounting bracket.

12...After drilling out the stubborn factory rivets securing the factory center crossmember, it is removed.

13..Check out the big 'n' bulky, crusty original center crossmember compared to the new CPP flat center crossmember with 4x5-inch exhaust pipe openings. The crossmember is notched on the sides to allow brake lines, fuel lines, or larger air lines to pass through and between the frame-rails.. Also, the new CPP center cross-member is available with a driveshalt bearing support.

14-15..Jeff drops in the new CPP flat center cross-member between the framerails with a little persuasion from a red rubber mallet.

16-17..To add needed strength to the frame-rail, a reinforcing plate is placed under- neath the framerail lip and secured with four bolts and nuts.

18..The center cross member is secured in place between the framerails. Notice the tubular trailing arm pickup point brackets have been moved up 4 inches from stock; this will correct the driveshaft's critical pinion angle.

19-20..After pressing in the two urethane bushing halves, Jeff aligns the rear tubular trailing arm into the crossmember mounting bracket.

21..Jeff and Danny Nix align and insert the new CPP U-bolt around the rear axle housing while sandwiching the 2-inch lowering block to the tubular trailing arm.

22..A pneumatic gun is used to secure the U-bolt around the lowering block and rear tubular trailing arm.

23..The rear axle track bar is located and secured to the passenger-side rear tubular trailing arm.

24..We can observe the new CPP track bar installed behind the rear axle housing.

25..A C-notch plate is used as a pattern to trace the opening for the C-notch using frame holes as location points for the plate.Before using a plasma cutting torch to cut the C-notch, it's important to mark the location of the cut and support the frame's rear portion.

26..Using a handheld plasma cutting torch, Jeff continues to cut out the C-notch in the framerail.

27-28..After the C-notch has been successfully cut, it is removed.

29-30..The precision jigged C-notch reinforcement plate is aligned and test-filled.

31..A transfer punch locates the pilot holes, which are then drilled in the framerails. The pilot holes are then drilled with a larger 1/2-inch drill bit.

32-33..After all the 1/2-inch holes have been drilled, eight bolts are installed, then secured with a lock washer and nut.

34..To eliminate metal hitting metal, a urethane bump stop is located inside the C-notch.

35..A shorter CPP coil spring is installed on the lower framerail.

36-37..To control the osculation and dampen the rear suspension, a pair of new CPP gas-filled shocks were installed.

38..A view from above shows the tubular tailing arms tapering into the center crossmember shorter coil springs and a rear track bar are all very important components in completing the CPP rear suspension equation.

39..A worm's-eye view shows the CPP rear suspension tubular trailing arm kit.

Go To Part Two