I was reading a forum and it was mentioned that a stock chevy distributor with points needs a timed vacum port and a HEI should have its vacuum hooked to a ported source. My question is, Is a MSD ready to run distributor considered HEI and should the vacuum advance be connected to a ported vacuum or constant vacuum ? I have a MSD ready to run distributor that has the vacuum advance hooked to the timed vacuum port of a Edelbrock 1405 carb. I do have a flat spot on accelaration after comming out of a turn at an intersection, now I'm not sure if I have the Vacuum in the right port ? Any and all help would be appreciated.