this may be a dumb question but.... can you use vacuum to actuate a dual port WG
 

its going to be part of a two gate set up on my older dodge cummins diesel to control a he351 VG holset manually, i don't need boost control as i am not throwing enough fuel at it (yet) to cause problems, one gate will be pressurized and be controlled with a bleed valve normally to open the housing allowing the exhaust to flow and keep egt's down, though a seesaw linkage i want the other gate to be able to pull the vg rack (using the other actuator as a pivot point) into the exhaust brake part of its travel, a few solenoids and switches to vent and close the appropriate lines and it should be down to tweaking the positions of linkages and bleed valve settings to get it running

i suspect that you can use vacuum to run one but have never tried and will likely need something stronger then the average hvac flapper motor, and it needs to have a decent parked position to act as the pivot point for the opposing actuator when it is not in use