How do you determine oil pan capacity?????

How do you determine the oil capacity in a dragster pan? Can you fill it with water up to the baffle to find out how many quarts it will hold? It is a very nice pan but, I do not know what brand it is.It is 4 3/4" at the front,and 5" at the back,8" wide,21" long.
My 8 quart Indy pan is 3 1/4" at the front,and 4 1/2" at the back,8" wide,21" long.Thanks!

You could try to calculate it but as long as it's apart, water and measure is your best bet

Preferably without wasting any alcoholic beverages....

Is the fill point the bottom of the windage tray? I am not sure where to fill it to. Thanks!