So I took my 38' Scarab out on its maiden voyage today .It has 575sci motors with aeromotive fuel pumps and regulators on it. Unfortunatly the motors have different vac sources to the fuel pressure regulators. One has it sourced from the throttle body ( above and before the blower) and the other is tapped into the map sensor wire (below and after the blower). I was told by the engine builder to set the fuel pressure to 28-30 lbs wot. Obviously the both react differently to throttle ,so which is correct? The motors are, unfortunatly, different generations ( one has two iac motors and the other has only one, and the air filters are slightly different.)but I don't think that makes a difference. Any help would be appreciated. Mike

I'm sorry in the last post I ment Map sensor "hose". Mike

Did you every resolve this issue? I am looking at installing a regualator on my single IAC motor.

the vac hose tees into the map sensor hose as close to the manifold
as possible. I sent the ECM from my single iac equipped motor to derebery performance to be reprogrammed and a second iac motor will be added along with an adapter harness to upgrade. Should be shipped back to me next week hopefully.mike