Rear Spacer & Coil Install:

Stock 1999 Toyota 4Runner rear spring and isolator/bump stop cone.

Cornbred 2" aluminum rear spacer & stock spring.

Daystar 2.5" poly rear spacer & stock rear spring.

Downey 3.5/2.5" coil on the left - ARB/Old Man Emu Heavy Duty 891 coil on the right.

ARB/Old Man Emu Heavy Duty 891 coil & ARB/Old Man Emu 10mm rear spring trim packers.  Part number: OME80PF10

1" Cornbred Rear Spacer on the left and OME Trim Packer and Toyota Cone on the right.  The Cornbred spacers seem to provide a more solid lift, the trim packers seemed to sag.

OME 891 rear coil and 1" Cornbred spacer.

Jack up the rear of the vehicle and secure with jack stands & remove wheels.

Disconnect the rear sway bar from both sides frame mounting points.

Disconnect lower shock mount bolt and support the axle with a floor jack.  If you need to remove the rear shocks to replace them, here are some helpful hints.  First off, the stock Toyota rear shocks use an all metal upper lock nut.  Breaking it loose is no easy task.  Aftermarket shocks are easy to remove, it's just the original set that comes with the truck that is difficult.  What I have found to be the easiest way to remove them is to put a 14mm Deep socket on the top nut with a standard 3/8" drive wrench.  Then grab the top metal dust cover of the shock under the frame rail, the cover is welded to the shaft, and twist the dust cover to break the nut loose.  The socket/wrench will find a spot to hold it up above the mount.  Of your truck is from or is in the "rust belt" a Saws-All or Plasma Cutter my be your solution.

Lower the axle enough to remove the spring and rubber cone.

Rear Cornbred 2" aluminum spacer install, compress the spring a little and reinstall minus cone with the spacer at the top.

Rear Cornbred 2" aluminum spacer install, Jack axle back up into position, re-install shock bolt & sway bar ends.

The exact same install steps are used for the Downey rear coils. 

The Downey 3.5" rear spring kit gives 2.5" of lift on a 4WD 4Runner and 3.5" on a 2WD 4Runner.  The kit includes the Rear Coils, Rancho Limiting Straps, Emergency Brake Bracket and various hardware to install the lot. 

Personally I think the Downey engineers are on to something here.  No matter what shocks or springs you have. I would take a look at what they have to say.  Step 19 of the Downey instructions. 

Upper tab dimensions: The tab is 3/16" thick steel but you could use 1/4". It is 2 1/4" long and 1 1/2" wide. The hole is 1/2" and is 1 1/2" from one end and 3/4" from the other. The end that is closer to the hole is completely rounded, the other end is completely flat. Use the Downey instructions for the exact placement. The original pieces were actually made by Rancho and were part of a limiting strap kit. As seen in the Downey instructions the Rancho tab is sort of a boot shape. This tab does not require this shape and both sides can be streight. 

The exact same install steps are used for the ARB/Old Man Emu rear coils.  Notice I retained all of the Downey "tweeks" with the OME parts.  The limiting straps are 2" longer than the Rancho straps to allow for the additional 1" of extension on the OME HD shocks.  When you install the Old Man Emu 891 coils, they will more than likely be labeled for a vehicle not sold in the U.S.  The correct placement of the coils REGARDLESS of any labels is the longer/taller spring goes on the drivers side, same side as the gas tank.

I had to grind smooth 1/2 of the grip section on the lower rear Old Man Emu shock so it did not fray the limiting strap.  The Bilstein shocks are smooth in this area.

Installation complete.