That would take R-12. although r-12 is very pricey nowadays. R-134a is much cheaper, but if would need a full retrofit
R 12 refrigerant.
If you are unsure use Ester oil. It is safe for all systems and chemicals.
r134
R-134
R134a
r12
The 1996 Suburban uses r134 Freon. The fittings to add Freon are different sizes on r12 and r134, making it impossible to add the wrong type to your vehicle.
11 oz
A 1989 GMC Suburban typically uses R-12 refrigerant for its air conditioning system. However, due to environmental regulations, many older vehicles have been retrofitted to use R-134a refrigerant. If you are working on a 1989 Suburban, it's important to check whether it has been converted to R-134a or if it still uses the original R-12 system. Always follow proper procedures for handling and disposing of refrigerants.
64 ounces of 134A is the capacity of the 1996 2500 suburban dual air system......
If you are having to add refrigerant, then this means you have a leak, and you will be adding refrigerant again in a few months. It is illegal to add refrigerant to a system with a leak without first repairing the leak. So, my advice is to take it to a professional and have the leak repaired and refrigerant added with the proper equipment, which you do not have.
Virtually all vehicles since 1994 use refrigerant r-134a. On a 97 Suburban, the suction (low pressure) and discharge (high pressure) ports are located on top of the compressor. Refrigerant is added to the low pressure side. It is attached to the larger refrigerant piping and hose which runs to the accumulator-drier at the firewall. The smaller high pressure pipe attaches to the condenser located in front of the radiator. Do NOT attach a refrigerant can to the high pressure line.