When I purchased my 69 Z/28 the Booster line was hooked to the Holley 780 base on the passenger side and the PCV line was on the back of the stock Winters intake. Vacuum was at 8-9 HG. Was told that was backwards so changed lines around and idle jumped up by 400rpms. Vacuum can numbers jive for that engine but have installed a Pertronix III to try to maintain stock look. Haven't re-checked timing but that's next.