2002 LS 6.0 Return vs. Returnless fuel system. What needs to be changed in ECM???

I'm going from a returnless fuel system to a fuel return type intake on a 2002 6.0. I'm not sure what needs to be changed on the ECM but rumor is something does. When I got the motor, the seller wanted to keep the returnless intake so I'm using a stock fuel return type intake. Fuel Injectors were the same stock on both intakes p/n 25317628.

Confusing since a 2002 6.0 would have had a return type fuel system. If using stock size injectors just look at the tables in a stock 2002 6.0L calibration.

Wrong forum, but...
Fuel -> General -> Flow Rate vs. KPA