You have only given part of the information needed. Ok, you have a 124 v-twin engine, is it an EVO or a TC? Who manufactured the engine case? What oil tank are you using? Is there an oil cooler involved? Many variables.
To answer the question, it is an H&L 124 ci Evo style engine, no oil cooler, chin spoiler oil bag that holds 3 plus quarts (my estimate). Just curious how much the block holds at any one time so I don't overfill the system.