I'm assuming you are referring to your modified/custom AC system with the engine swap? If so, the proper amount of refrigerant for that will not be the same as for any original or standard system. With a custom made AC system you cannot go by the weight or specific quantity of refrigerant, it may be too much or too little - both of which will result in suboptimal performance. Instead the best method in a case like this is to go by measuring the temperature at specific points on the system while you add refrigerant. And those temps will tell you when it has the correct amount for that particular system.
The measurement points are the two ends of the low pressure line between the evaporator and the compressor. Measure as close to the evap and compressor as possible, and when the temp at those two points become equal it is done. Also follow the pressures on your manifolds to make sure you do not exceed the safe limits as you fill it.
As for the amount of oil, that is also a bit difficult to answer on a custom built system. The 'standard' method for a stock system is to follow the manufacturers recommended quantity, but that doesn't apply here. Another is to measure what comes out of the system and put the same amount back, but that also does not apply. Each of the major components (compressor, condenser, evap, receiver/dryer, etc) will require a specific amount based on their size. So one method is to compare the measurements (size) of those components to a chart to estimate the total amount of oil. Some of the components like the compressor will have specifications for the proper amount for that particular component model. You can find that on the compressor's manufacturer site. The rest can be estimated from the sizes. Note that most new compressors come pre-filled with oil, so take that into consideration. Make sure the type of oil you use is compatible with any existing oil in any of the components and with all the other parts of the system, as well as the refrigerant, that you have.
Sorry this isn't a direct answer to your question, but honestly there isn't one if you are working with a non-stock system that you assembled. If it helps I can refer you to a couple of very experienced experts to consult...that's where I got this information.