Replacing compressor and adding refrigerant to my old car.

I have a car that I am replacing the compressor on. I plan on evacuating the system down using a vacuum pump. I have a can of R134 with 13oz of freon and 2oz of oil. I bought that primarily to add the oil. I plan on topping off the system but need to know the capacity to make sure I don't overfill and take out gaskets or hoses and to make sure I have it full.
Do you know the capacity of my totally evacuated system or is it listed somewhere under the hood? Also, how do I check and make sure the system doesn't have any refrigerant leaks?

Thanks!!!

Replacement compressors usually come with a FULL CHARGE of about 6 to 7 ounces of refrigerant oil. You need to drain out the old oil from your old compressor and measure the amount that you drained out. Next you need to empty out all the refrigerant oil from the NEW compressor using a tool like the Robinair CoolTech and reinstall the EXACT same amount of refrigerant oil that you got out of the old compressor and install it into the new compressor. Do NOT use the old oil from the old compressor. Use the NEW oil from the new compressor. There is a sticker located somewhere on the underside of the hood or on the firewall that tells you the MAXIMUM amount of oil that your complete system contains. After you add the refrigerant to the system, you can then use a refrigerant leak detector to sniff out any leaks. There are several models out there and each has it's benefits. Check out the list at Red Hill Supply and we have several different models to choose from.