The spindle will need to be slightly clearanced to clear the lower shock once at ride height. Grind around 5/8″ up from the bottom of the spindle.

See the mark on the spindle for the area to clearance. Only need to take about 1/6″ of material.

Install the shock inserts, then the 1/2″ lower onto the lower plate and torque to 60 ft/lbs. This will not be accessible once installed on the lower control arm.

You can install the sway bar end links now for ease of installing the lower bolt, or install after mounting the lower plate to the lower control arm. We installed the end links before mounting the plate.

To install the shock, the upper portion must go in first. Hold the spindle away from the frame to gain enough clearance for the shock clear the control arm and the lip on the frame.

The upper clevis is offset for spring clearance. Ensure that the offset is pushing the eyelet of the shock towards the outboard (wheel) side of the car.

To install the lower mount, by pressing down on the lower control arm while holding the spindle away from the frame. Install the top two retaining bolts as the one next to the end link is very tight.

Next, lift up on the control arm to reinstall the lower ball joint and tighten the lower mount bolts. Tighten the two top mount bolts, and torque to 35 ft/lbs followed by the one on the side by the sway bar mount. The fourth hole is optional but recommended for additional strength.

Tighten the upper clevis next. You’ll need a 10mm wrench to keep the clevis in place. The eccentric washer will need to have the thin side towards the outside of the car to maximize spring to frame clearance. Torque the M14 nut to 50 ft/lbs.

These bolts all take a 13mm socket or wrench.

Completed unit, ready for ride height adjustment.

Before installing the upper sway bar end link, you’ll want to set final ride height. Loosen the jam nut and spring collar to desired height. The shocks ship with the spring only hand tightened so the spring doesn’t rattle during shipping. This should be near factory ride height though.

The car will need to be rolled or driven a very short distance to get the suspension to settle. Typically 100-200 ft should be plenty. Adjust ride height as needed and settle the suspension each time.

After driving on a four post lift or up on ramps, install the upper sway bar end link. The suspension will need to have the full weight of the car to properly adjust the end links. Position the sway bar at the desired height and adjust the end links accordingly. Tighten down, align the car and you’ll be ready for a new riding and/or handling early model C4 Corvette.

Remove the carrier bearings, ring gear, plates and springs, then clutches.

Chuck the posi in a lathe and ensure it’s centered. Dial indicator is to make sure the unit is running true on the lathe before machining.

Standard ID on the posi is around 1.247″.

This will need to be opened up to a diameter of 1.295″ for the new axles with a step cut coming next.

Your posi should now have a bore of 1.295″ and a step that is 1.395″ on the outer edge of the bore that is .325″ deep. This allows the new side yokes to be pushed in far enough to install the 12 bolt c-clips during assembly of the differential.

Finally, sand or file the hard edges and clean the posi before re-assembling.

1. With the factory sway bar removed, install the rearward bolt on the thin part of the adapter bracket. Install both brackets hand tight.

2. Install the poly bushings on the sway bar making sure to lubricate the inside of the bushing very well.

3. Feed the sway bar through the cradle.

4. Place the forward most bolt in next. This bolt goes all the way to the frame. Make sure to place the provided washer between the gold bracket and the relocation bracket. This keeps the bushing bracket from pinching the sway bar bushings and limiting rotation.

5. Install the reward bushing bracket bolt. This image shows the washer that goes on top of the bushing brackets.

6. Torque down the 6 frame mount bolts until securely snug.

7. After the bushings are snug, grab the end of the sway bar and rotate the bar up and down. There should be some resistance to the bar. You want to make sure it doesn’t freely move up and down with little resistance or is overly hard to rotate the bar.

8. You’ll you need to remove the lower sway bar bushing in the control arm next. (instructions for this coming soon)

9. Install the aluminum lower sway bar bushings and the end links on the lower control arms only then bolt on your front wheels

10. Set the car down on ramps so you can adjust and install the upper bolt on the end links. The rearward most hole will be the softest setting and the inward most hole the stiffest. You may have to use the soft setting to clear the tie rod ends. Double check that all your bolts are tight and set the car on the ground.

11. Finally, turn the wheels full lock in each direction and check your endlink to tie rod end clearance. You may need to adjust the gold sway bar brackets to give your self more clearance at full lock.

Delrin Cross Member Bushings

When installing the Delrin differential cross member bushings, we recommend using a little bit of grease on the OD of the bushing. You will need a press or arbor press to install the bushings. Make sure the bushing goes in straight. You may need to take a die grinder to open up the ID of the cross member hole. This process may need to be done due to rust scaling and/or paint in the cross member. The bushing should never have “play” in it. If it does, the cross member holes are elongated and you should source a new one. 

In rare occasions we have found there is an air gap between the delrin bushing and the SG-47 plate. Install one large washer per side so the SG-47 plates no longer have an air gap.

SG-47 Reinforcement Plates

You have to have these style plates to retain the delrin bushings. If you do not have these plates, you’ll need to order the SG-54 kit or if you already purchased the SG-53 kit, you’ll need to order our SG-47 plates.

Install the studs after the differential cross member is installed. The coarse threads go into the frame. Install the aluminum disc/flat wash/lock washer & nut. Torque the nut to 30-35 ft/lbs or yeild. Recheck the torque after 50 miles or after the 1st event. If your kit came with all four nuts and washers like shown to the left, you’ll discard two nuts and two flat washers.

Pinion Bushing

Install these bushings as you would a factory bushing and torque to factory spec. We include an Upper Poly Bushing and a Delrin Lower Bushing. Torque to 70 ft/lbs.

left graphic: Orientation is set as would be in the car. The thick part of the bushing should go up into the frame mount. Make sure to check that your crossmember needs the washer between the bushing and the SG-47 plate

To determine which side is LH & RH, place the bearing support on a table with the outer bearing on the table and the legs facing you like shown above. The legs will have 2 holes for the shock mount to pass through. One is a 3/4 hole (D shaped hole), the other is a full circle. The side with a flat will determine if it’s a LH or RH bearing support. The side with the flat will be towards the back of the car.

1. Put the bearing support in a bench vice with the outer bearing facing you. The inboard side will have a silver dust shield on it.

2. Install the trailing arm with the 4 mounting studs pre-installed. Make sure the flat in the shock mount hole is towards the back of the t-arm.

3. Install the caliper mounting bracket. Be careful here b/c caliper
mounting brackets are LH & RH as well. The long flat should go
toward the front of the car. ***Pro Tip If you have a packing
peanut/small piece of cardboard/paper, put it in the divot on the
caliper mounting bracket and tape it in place with masking tape.
This will prevent the Parking Brake Side Pin from falling into the
hole which makes it difficult to install the side spring.

4. Install the backing plate with BOTH side pins. We recommend that you tape both on with masking tape or alike.

5. Install the 4 lock washers and nuts onto the 4 t-arm mounting
studs. Do not tighten

6. Install the parking brake anchor block with guide plate (wings up) and ½”-20 bolt.  Torque value is not critical here b/c there is no load on the bolt. If a value is needed, 60 ft/lbs is sufficient. Bend the 2 top tabs up to the side of the bolt. This prevents the bolt from loosening up.  ***Pro Tip Use an adjustable wrench and place it over the anchor block. Make sure the long flats on the anchor block are parallel to the ground if you will. As you tighten the anchor block bolt, the wrench will prevent the block from rotating.

7. Torque the 4 mounting stud nuts down. – 35 ft/lbs

8. Install the parking brake hardware and shoes. We like to put the star adjuster on the RH.

9. Remove the assembly from the bench vice and set it on top of the spindle. Once the spindle is in place, set the 2 pieces into a press. Place the spindle flange on top of the spindle and begin pressing the spindle into place. After a few pumps on the press, make sure the splines on the spindle flange are aligned with the splines on the spindle. Once that is aligned continue pressing the assembly together while rotating the assembly left to right until fully seated.

10. Remove the spindle flange and carefully remove the assembly from the press and place it back into the bench vise.

11. Install the rotor with lug nuts and aligning the parking brake hole in the spindle to the parking brake hole on the rotor. If the rotor does not have a parking brake hole, STOP and find the correct rotor. All 65-82 rear rotors will have a parking brake hole, front rotors will not.

12. Using a dial indicator with a magnetic base, place the indicator on the outer most edge of the friction surface. The rotor runout needs to be .005” or UNDER. If the runout is higher, you need to diagnose the problem and see if it’s the rotor or the spindle being used. If the spindle has a high run out and it’s already been pressed in, it needs to be removed and replaced. If it’s removed, new bearings are recommended since these bearings are a press fit and defeats the purpose of why you purchased a built assembly in the first place. If the runout is in the rotor, find the high spot and grind it out on the mating surface side.

13. Once rotor runout is completed, mark the spindle and rotor.

14. Install the spindle flange with washer and nut. Torque to 100 ft/lb. If the cotter pin hole doesn’t line up, GO TIGHTER.

15. The assembly should be complete and ready bolt into the car. We recommend removing the rotor for installation. It’s 20 lbs lighter without it on. Once the assembly is in the car, you can install the rotor by aligning the 2 marks you put on the spindle and rotor. Secure it with a lug nut until the tire is ready to go on.

To install the DK-200 plates, you’ll need to lift your Corvette in the air via jack stands or lift.

Remove exhaust if it interferes with the clearance of removing the bolts. Support the transmission with a trans or floor jack before removing bolts.

Remove the M12 course thread factory bolts using an open wrench above the transmission and a socket on the bottom side. Should be an 18mm wrench and socket.

Some models, seems to be only manual transmissions, need to slightly open the hole from 12mm to 1/2″ for the provided hardware. Automatics seem to have a larger hole or have wallowed out over time. You’ll need a 1/2″ drill bit 7″ long.

Install both 1/2″ fine thread 7″ bolts through the two hole plate with the smaller holes sliding them through the C-beam on through the tail shaft.

Before seating the bolts all the way up, place the top plate with stover nuts welded in on top of the c-beam.

You may need to use a rubber mallet to encourage them to seat all the way in. And start the bolts by hand or wrench.

Tighten up the two bolts alternating back and forth tighten each one a little at a time to ensure it seats properly. Torque to 80 ft lbs.

Leaving the jack under the transmission holding the c-beam in place, loosen the differential bolts and remove.

You may have to pry the c-beam and differential to line up the holes for the provided 9/16″ x 8″ grade 8 bolts. These holes will not need to be drilled out.

Place the bolts through the two hole flat plate and place up through the c-beam and through the differential. Bolts shown here compared to factory course thread metric bolts.

Place the top plate with welded nuts on top and start the bolts by hand or wrench.

When tighten bolts, we suggest tighten up a little at a time alternating bolts until snug. Torque the fine thread bolts to 110 ft lbs.

If all other components are in fair shape, your car should track nice and straight during hard acceleration. This kit should reduce side kick when launch the car hard.

First, start with the lower a-arms. The flat part of the shaft goes against the frame. There is a bolt that comes in the lower control arm cross shaft (Figure 1). This bolt goes toward the rear of the car. There is a top hat style reducing washer. Remove the bolt and washer from the arm and drop it through the frame bracket. The top hat part of the washer should face down. This washer is designed to reduce the gap of the OE hole to accommodate the 1⁄2” bolt supplied.

Moving toward the front side of the arm you can install the aluminum cradle bracket that is supplied with the (Figure 2) 7/16-20-1.5” Allen head bolts and lock washers. You are to re-use your existing 2 hole plate that came on the car. You will need a 3/8” Allen head socket/wrench/T-handle to tighten these down. (Figure 3) Do not torque these yet as you should move to the rear bolt again and torque it 1st. Torque the rear bolt to 60 ft/ lbs. (oiled) and the front bolts to 40ft/lbs.

The ball joint is going to sit further back in the car than the OE upper a-arm. Shown in Figure 4 is a left front upper. Align the holes in the cross shaft to the alignment studs in the frame. (We recommend using a rubber mallet as these bolts can be tweaked a little bit and you may need to hit a stud forward or backward.) If the studs are out and you are installing new studs, slide the a-arm into po- sition and push the studs through the frame and through the cross shaft by hand until you get to the knurl of the stud. Place the 7/16” flat washers over the stud and thread the alignment nut onto the alignment stud and drive the studs into place so that they are seated. Once the studs are seated, tighten the alignment nuts. For starters, you can use a 1/16” shim on the front stud and a 1/16” + a 1/8” shim on the rear stud. Once you get the car aligned, the alignment shop will correctly place the correct size shims be- tween the frame and the cross shaft. Refer to the Alignment Spec Sheet at the end of the instruction packet.

<- On top of the Coilover is a clevis mount. The mount will have 1 flat washer and a flange pinch nut. Remove the nut as the washer will stay on the top of the mount. (Figure 6)

Next, slide the shock into place. You may need to grind the threaded section of the bolt that goes through the clevis to go up through the hole in the frame.

Once the shock is in place and the stud is through the OE shock hole, install the flange nut that you removed before you started the install and tighten so the stud engages the pinch nut. Make sure the head of the bolt (Figure 7) is facing the front of the car. You will need a pry bar or screwdriver to hold the upper clevis from rotating as you tighten the nyloc nut (Figure 8). Torque to 40 ft/lbs.

Install the lower ball joint on to the bearing assembly spindle and thread the nut on.

Next, place your floor jack under the lower a-arm with a block of wood. (Figure 9) Jack the arm up until you have clearance to insert the upper ball joint into the spindle. Once the stud of the upper ball joint is through the spindle, thread the nut on. ***PLEASE NOTE THE CAR MAY START TO LIFT OFF THE JACK STANDS/LIFT. 

Once the front assembly is on you can refer to your assembly manual on how to install the rest of the steering parts (i.e., tie rod ends, center link etc).

On the lower a-arm, remove the 1⁄2” bolt and nut from the shock mount. Loosen the spring collar all the way down and make sure your valving is at zero. Now you can compress the shock to line up the shock mount hole with the bracket for the lower mount. Slide the 1⁄2” bolt through the hole and install the nut. We use a long bolt here because we like to get as much of the shank of the bolt through the shock as possible because it’s stronger. Torque to 50 ft/lbs. Retighten the spring collar up until it gets hard to tighten by hand. This should put the car just under factory ride height depending on the spring rate and weight of your Vette.

Now that your system is installed minus your sway bar end links, you’ll need to adjust the springs to set your ride height. The system ships with the springs just hand tightened. This is typically a good starting point and should allow for around a 1” drop. If you want a closer to factory ride height, I’d go up on the collar 3/4”. 

The shock shown to the left is just hand tightened and is our recommended lowest starting point.

When adjusting coilovers, make sure you disconnect at least one end link so the sway bar doesn’t hold up any ride height changes.

DO NOT install the front end links on the sway bar until the car is at the preferred ride height. At least one end link should be disconnected when adjusting ride height.

The 1 1/8” bar (which works well for all models using 215-225 width tires for C2 or 225-255 on C3s) uses rod ends for end links for better sway bar orientation when altering ride height. Figure 10 shows how the end link hardware should be oriented on the lower control arm.

The dip in the sway bar should dip down away from the radiator. The end links should mount to the inboard side of the sway bar to keep them as vertical as possible.

To set up the heim end, you must first have the car at ride height (ramps or drive on lift). Next choose your sway bar stiffness (two hole adjustable), the closest to the end of the bar will be the softer of the two settings. You’ll want to setup the end link to be as close to perpendicular to the ground as

you can. Once both end links are installed, you should be able to rotate the heim with minimal to no binding (by hand or with a wrench). Enjoy the upgraded handling of you Corvette!

Tools Needed

5/8 socket, 11/16 socket
15/16 wrench, 11/16 wrench

Remove nuts and washers from the frame mount bolts for the upper control arms. You want the brackets to sit flush with control arm shafts.

Install the brackets (use provided flat washers) and fasten your factory hardware to 50 ft/lbs using the 11/16 socket or wrench.

Install inserts into the rod ends on one side only to start. These are a slip fit and fall out easily.

Insert the rod end into the bracket and slide your bolt down to retain the rod end.

Install inserts for the other side and install into the bracket. Fasten your hardware.

Tighten hardware until snug. No more than 50 ft/lbs is needed.

Tighten the jam nut snug with the 15/16 wrench. The adjustment bar does not have slots for a wrench as it only needs to be held on by hand.