You're going to have to find a return style SVT LIM and swap over your vacuum solenoid for the secondaries onto it. And then use the 19lb'ers if you want or if you want to go 24 lb it's going to be a bigger headache as you will have to use an SVT return fuel rail AND splice on new injector connectors from the 3L harness over to your harness and swap over the secondary attachment too. Good luck!