Just for your reference you can use GM supercharger oil and it is sold in 4oz amounts which to my knowledge is the right amount.
From Eaton:
Q: How often do I need to change the oil in my supercharger?
A: The sealed oil reservoir in a supercharger is designed to last the life of the vehicle. Changing the oil is not recommended unless you suspect contamination, leakage, or other issues like bearing failure. Also, if your vehicle has an abnormally heavy duty cycle, such as racing or towing, you could consider changing the oil at regular intervals such as 20k (32k kms), 30k (48k kms), 50k (80K kms), or 100k (120k kms) miles depending on usage.
Q: I’ve decided I need to change the oil in my supercharger. How do I do this?
A: If you do want to change the oil there is one fill/drain plug on the front face of the front cover. It will probably be an Allen type plug. You will have to suction out the oil using a syringe or other method before replacing with new oil. Fill levels are dependent on application. For aftermarket units, please consult the aftermarket partner company that produced that specific kit. For OEM units, please see the list below or email infosupercharger@eaton.com. New oil can be obtained from any GM or Ford service parts facility, or from one of the Eaton aftermarket supercharger partner companies or remanufacturers. Please make sure you do NOT use any other type of oil, including synthetic motor oils. These will cause failure.
