RotorsRulePistonsDrool

I am running the cosmo 13b-re engine adn I have none of the wastegate actuators. I want to run a manual boost controller and I do not know which of the 3 actuators controlls the overall boost of booth turbos. There is one on top and 2 on bottom. One is a turbo precontrol and I do not want to use that at all as I am running non sequential twins. So my question is, which actuator should I set the boost controller to control both turbo's pressure? Thanks