Marcus
The throttle bodies will provide enough Vacuum in the same way the GC inlet manifold does for twin 45 DCOEs. However expect heavy pulses if you connect to 1 cylinder runner only. Not an issue for the brake servo with the one way valve but you will need a damper for the MAP sensor. sometimes Rolling Roads use a plastic carb fuel filter to do this or a MIG welding nozzle inserted in the pipe to the MAP sensor.
Enjoy
Eric