GMC 1996 Sierra Owner's Manual page 326

J 28.5 quarts (27 L)
Fuel Tank Capacity (Approximate)
Type
Quantity
Short Bed
....................
. 2 6 gallons (98 L)
Long Bed
. . . . . . . . . . . . . . . . . . .
. 3 4 gallons (128 L)
Standard Crew Cab
. . . . . . . . . . .
34 gallons (128 L)
Chassis-Cab Side Tank
.
. I
. . . . . . . .
23 gallons (87 L)
Chassis-Cab Rear Tank
. . . . . . . . . .
17 gallons (64 L)
3500 HD Models Side Tank
. . . . . . .
23 gallons (87 L)
3500 HD Models Rear Tank
. . . . . . .
18 to 20 gallons
(68 to.76 L)
-Air Conditioning Refrigerants
Not all air conditioning refrigerants are the same.
If the air conditioning system in your vehicle needs
refrigerant, be sure the proper refrigerant is used.
If you're not sure, ask your GM dealer.
See the refrigerant charge label under the hood for
information regarding refrigerant capacity.