vacuum advance question

Well, I emailed the manufacturer about the one in the link and here is what they had to say-

"Our BWD V194 is not technically adjustable. There is an Allen screw inside the vacuum port, but it is factory set, and has Loctite on it. You would have to adjust it at your own risk, and will need to add Loctite to maintain position. We do not recommend this. Unfortunately, we do not offer an adjustable model for this vehicle. Sorry we couldn’t be of more assistance."