[olddog]

600 rpm = 10 rev/sec = 5 intake strokes per second. Put a vacuum gauge on a single port and see how much pulsation you see. You might be able to dampen the pulsations by adding a vacuum canister in the line. However it will add lag time between when the vacuum changes at the engine and when you see the change on the other side.

Some guys on here have posted pictures of plumbing under the intake with stack injection. I have to assume the pulsation is a problem or they wouldn't go to all the trouble. I would say that EFI would be more sensitive to pulsations and lag time than timing would be.