jhv48 J here's something to think about, Unless you get high flow connectors, the line size will not change a thing with flow. All you will do is store more
oil in the lines by going up a size. Can add an extra 1/2 quart of
oil to the system with this change. Every adaptor you add to the system only slow and restricts flow. IF you are looking to increase flow enlarge the insides of the fittings. Even with #10 or #12 lines the fitting are about 3/8" ID. Same applies for the oiling system in the motor. Depending on what modifications are done to the block and heads. IMO the most important things are to get good supply of
oil to the bottom end. Have limiters to the valve train but have enough oil to cool the valve springs. Clean the motor of casting for quick return to the oil pan. Depending on what motor block you have a windage tray add extra oil holes for oil return to oil pan or no tray at all. If you race alot, this very important. Don't idle the motor if you are running solid lifters or even hydros, with or with out rollers.
Last note look into a accusump for prelubing the motor and or autocrossing the car. 85% of all wear is done from startups. I add a bottle of Lucas oil suppliment to my oil. Make sure motor is warn and pour in slowly to get good mix. You loss a couple of HP but save the motor on startups. Good luck Rick L.