Here you go:
RECOMMENDED FLUIDS AND LUBRICANTS
Engine Oil - API "Certified For Gasoline Engines"
Viscosity - 5W-30 Recommended, 10W-30 Okay if 5W-30 Unavail.

Fuel - Unleaded Gasoline - 87 Octance Minimum

Automatic Transmission Fluid - DEXRON III Automatic Transmission Fluid

Automatic Transfer Case
New Venture 236 NP8, New Venture 246-NP8 - GM Auto Trak II Transfer Case Fluid
Borg Warner 4481-NR3, Borg Warner 4482-NR4,
New Venture 149-NP, New Venture 149-NP3,
New Venture 263-NP1, New Venture 261-NP2 - DEXRON III Automatic Transmission Fluid

Differential
Front
Selectable 4WD - SAE 80W-90 Gl-5 Gear Oil
Full Time 4WD - SAE 75W-90 Synthetic Gear Oil
Rear - SAE 75W-90 Synthetic Gear Oil
Quadrasteer Rear Axle - GM Synthetic Axle Lubricant

Power Steering Fluid - GM Power Steering Fluid

Brake Hydraulic Fluid - DOT 3 Brake Fluid

Engine Coolant - 50/50 Mix of DEX-COOL Coolant and Demineralized Water

Parking Brake Mechanism Grease - White Lithium-Based Grease NLGI no.2

Chassis Lubrication Grease - NLGI Grade 2 or GC-LB Chassis Grease

Hood, Door, Trunk Hinge Lubricant - Lubriplate, lubricant aerosol spray

Door Hinge and Check Spring Grease - NLGI no.2 Multi-Purpose or Equivalent

Key Lock Cylinder Lubricant - Graphite Spray

Hood Latch Assembly Lubricant - NLGI no.2 Multi-Purpose or Equivalent

Door Latch Lubricant - NLGI no.2 Multi-Purpose or Equivalent

CAPACITIES
Engine Oil (inlcuding filter)
V8 - 6.0 Quarts

Manual Transmission
New Venture 3500 - 2.2 Quarts
New Venture 4500 - 4.0 Quarts
ZF S6-650 - 6.3 Quarts

Automatic Transmission
Fluid and Filter Change
4L60-E/4L65-E - 5.0 Quarts
4L80-E/4L85-E - 7.7 Quarts
From Dry, Including Torque Converter
4L60-E/4L65-E - 11.2 Quarts
4L80-E/4L85-E - 13.5 Quarts

Transfer Case
New Venture 246-NP8
1999-2001 - 2.4 Quarts
2002 & Later - 2.0 Quarts
New Venture 149-NP - 2.0 Quarts
New Venture 263-NP1 - 2.4 Quarts
New Venture 149-NP3 - 2.0 Quarts
New Venture 261-NP2
1999-2001 - 2.3 Quarts
2002 & Later - 2.0 Quarts
Borg Warner 4481-NR3 - 1.5 Quarts
Borg Warner 4482-NR4 - 1.5 Quarts

Cooling System
V8 Engine
4.8L and 5.3L - 16.7 Quarts
6.0L
Yukon Denali, Yukon XL Denali - 19.0 Quarts
All Others - 16.8 Quarts

BRAKES
Disc Brake Pad Wear Limit - 3/32 Inch
Drum Brake Shoe Wear Limit - 1/16 Inch
Parking Brake Shoe Wear Limit - 1/16 Inch

IGNITION SYSTEM
Spark Plug Type
1999
V6 - AC Delco 41-932 or Equivalent
V8 - AC Delco 41-952 or Equivalent
2000
V6 - AC Delco 41-932 or Equivalent
V8 - AC Delco 41-952 or Equivalent
2001
V6 - AC Delco 41-932 or Equivalent
V8 - NGK PZTR-5A15 or Equivalent
2002
V6 - AC Delco 41-932 or Equivalent
V8 - NGK PZTR-5A15 or Equivalent
2003
V6 - AC Delco 41-932 or Equivalent
V8 - AC Delco 41-974 or Equivalent
2004 & Later
V6 - AC Delco 41-932 or Equivalent
V8 - AC Delco 41-985 or Equivalent

Spark Plug Gap
V6 Engine - 0.060 Inch
V8 Engine
1999-2003 - 0.060 Inch
2004 & Later - 0.040 Inch

Firing Order
V6 Engine - 1-6-5-4-3-2
V8 Engine - 1-8-7-2-6-5-4-3