I have the Aviad pan. As you say, add 9 qts at first. Also fill your
oil filter(s) prior to installing them AND write down how much you used. Before you do anything else, not the
oil level on your dipstick. Make a mark with a hammer and punch, or drill a small hole a the
oil level. You also may be able to adjust the hieght of the dipstick instead.
Next, pre-oil by using a drill in reverse or cranking with plugs out. I always used to do the cranking thing,, but last time I found the drill and old dist shaft worked better.
Finally get your engine running. After you shut it off, leave overnight. Now add oil so level comes back to mark you made. Record the amount, or commit to memory if you have a good one....I don't.
Now, total oil is 9 quarts plus oil for filter's plus the bit extra you used to top it off.
Next time you do an oil change, you'll know the total, although it is likely you will only need the 9 qts plus filter amount as the rest will stay in the lines, galleries, etc. Regardless, you'll have a correctly marked dipstick to check the amount.