I took a trip today West MD to see the install of a system I built for a farmer and installed it on a 1991 Ford F-150. He modified the Bubbler and the reservoir to prevent the vacuum sucking the solution from the Bubbler and he is porting it through a vacuum line.
He did a good job with the install, drove the truck without the system activated, typical old 200K mile truck. Activated the system, it was night and day in the performance. So, share with me your "Pros N Cons" inducing HHO through a vacuum line. I think Richard is using a vacuum line.