Thanks for the replies. I'll have a look at the regulator, see how it is to strip it down. There is already a hole in the body, above the diaphragm. If it looks like adding a fitting there will foul the internal mechanism, then it cant be done. That particular model doesn't seem to have a boost referenced equivalent. I want to reference the regulator to the sealed scoop pressure. Not sure how much pressure it will generate but the combo is pretty sensitive to fuel bowl level.