Owners manual

1988-1995 GM Truck 4.3L/5.0L/5.7L

3 Piece Aluminum

Under-Drive Pulley Kit

Part #1603

INS-072

Follow these instructions carefully to ensure correct fitment and operation.

NOTE!!! This pulley system requires the use of a 6 rib 91.5” length serpentine belt.

Special Tools

Required:

•

No special tools

required

Install Time:

Approximately

2 Hours 30 Min

Difficulty:

3 out of 5

STEP 1

STEP 5

• Raise the hood and disconnect the negative

battery terminal.

STEP 3

STEP 2

• Using an air impact wrench, loosen and remove

the alternator pulley nut. Applying additional

tension to the belt will aid in keeping the

alternator pulley from spinning.

• Leave the serpentine belt in place and loosen

the crankshaft pulley and water pump pulley

bolts.

• Remove the stock pulleys from the vehicle and

simply reverse the process to install the BBK

Pulleys. Install all of the pulleys finger tight, and

then install the belt to tension while tightening to

factory torque specs.

STEP 7

• Re-install the negative battery terminal and start

the vehicle. Watch the belt carefully to ensure

proper alignment, etc…

STEP 6

STEP 4

• Carefully follow the belt routing to ensure that

the belt is tracking properly. It is very easy to

incorrectly install the belt with one groove off a

pulley; this would destroy the belt immediately!

• Remove the belt, and carefully note the routing

for re-installation once pulleys are installed.