Tuff Country 16730 - GM 88-91 1/2 ton Blazer / Sub 6 box kit User Manual
Page 4
 
19. Working on the driver side, move the stock hard 
brake line located in the inner part of the frame rail under 
the stock frame. Reconnect the hard line and the soft line 
back together around the new brake line extending 
bracket that was installed in step # 18. Repeat procedure 
on the passenger side. 
See Illustration # 6
 
20. Working on the driver side, install the new front 
shocks absorbers using the stock hardware removed 
from step # 2 . Special Note: Shocks are not included 
with this suspension system, shocks need to be 
ordered as a separate part number, Tuff Country EZ-
Suspension recommends using a 23” fully extended 
nitrogen gas shocks. If the vehicle that you are 
working on has the dual shock option, Tuff Country 
EZ-Ride Suspension recommends using a 26” fully 
extended cellular gas shock for the auxiliary shock. 
Repeat procedure on passenger side.
See Illustration # 6
21. Locate (2) front sway bar drop tubes, (4) 7/16” x 2 
1/2” bolts, (4) 7/16” flat washers and (2) 7/16” unitorque 
nuts. Working on the driver side, install the new sway bar 
drop tube between the stock sway bar and the stock 
sway bar mounting point. Secure using the new 7/16” x 2 
1/2” bolts and hardware. Torque to 35 ft lbs. Special 
Note: The front sway bar drop tubes are the tubes 
that measure 1” tall. Special Note: If the vehicle that 
you are working on does not have a stock front sway 
bar, please discard this step. Repeat procedure on the 
passenger side.
See Illustration # 7
 
22. Install the tires and wheels and carefully lower the 
vehicle to the ground. 
 
23. With the weight of the vehicle on the ground, torque 
the top and bottom spring eye shackle bolts on the driver 
and passenger side to 40 ft lbs. 
Front End Installation Complete
Rear End Installation
24. To begin installation, block the front tires of the 
vehicle so that the vehicle is stable and can’t roll forward. 
Safely lift the rear of the vehicle and support the frame 
with a pair of jack stands. Place a jack stand on both the 
driver and passenger side. Next remove the wheels and 
tires from both sides. 
 
25. Locate (1) rear brake line extending bracket, (1) 
5/16” x 1” bolt, (2) 5/16” flat washers, (1) 5/16” unitorque 
nut and (1) 5/16” lock washer. Remove the stock brake 
line bracket from the rear differential and save stock bolt 
for later re-installation. Secure the new brake line bracket 
to the rear differential housing using the stock bolt. 
Special Note: Make sure to use thread locker or lock 
tite. Next, attach the stock brake line bracket to the  
newly installed brake line bracket and secure using the 
new 5/16” x 1” bolt and hardware. Torque to 16 ft. lbs. 
See Illustration # 8
 
26. Position a pair of hydraulic floor jacks under the rear 
axle. Place one jack stand on the driver side and one on 
the passenger side. Raise up on both hydraulic floor 
jacks at the same time until they make contact with the 
rear axle. 
 
27. Working on the driver side, remove the stock shock 
and save the stock hardware for later re-installation. 
Longer shocks are needed, so the stock shocks may be 
discarded. Repeat procedure on passenger side. 
 
28. Working on the driver side, remove the (2) stock rear 
U-bolts and discard. Set the upper U-bolt plate a side for 
later re-installation. Repeat procedure on passenger side 
 
29. Lower down on both hydraulic floor jacks at the same 
time until the stock springs separate from the stock rear 
axle. Lower down approximately 6”. Special Note: Make 
sure not to over extended any brake lines or hoses 
when lowering the axle. This will allow you enough 
room for the new rear blocks and add-a-leafs to be 
installed. 
 
30. Working on the driver side, place a pair of “C” clamp 
vise grips on each side of the stock centering bolt. 
Carefully remove the stock centering bolt and nut and 
discard. Carefully remove the “C” clamp vise grips that 
are holding the stock springs together. Special Note: Be 
very carefully when removing the “C” clamps, the 
stock springs are under tension and can be 
dangerous. Repeat procedure on passenger side. 
 
31. Locate (1) new rear add-a-leaf, (1) 3/8” x 5” centering 
bolt and (1) 3/8” fine nut. Install the new rear add-a-leaf 
into the stock spring assembly. Secure the new rear add-
a-leaf to the stock spring assembly using the new 3/8” 
center bolt and nut. Torque to 28 ft. lbs. Special Note: If  
the new add-a-leaf that you are installing into the 
stock spring assembly has an offset center hole 
location, place the longest side of the add-a-leaf 
towards the rear of the vehicle. Also the new add-a-
leaf should be installed into the stock spring 
assembly in progression in order, from longest to 
shortest. The new add-a-leaf should be installed 
between the stock overload and the stock spring 
pack. The stock overload is usually the un-arched 
spring at the bottom of the stock leaf pack. Also Tuff 
Country EZ-Ride Suspension recommends not using 
any air tools when installing the new add-a-leafs into 
the stock spring assembly. If air tools are used the 
centering bolt may strip, causing the stock spring 
assembly to come apart. With a suitable cutting tool, 
cut off the extra thread from the new centering bolt. 
Repeat procedure on passenger side. 
See Illustration # 9