I have a 69 Z28 with it's original 302. Before my ownership someone stuck a cam a bit different from the original Duntov 30/30 cam. Engine suffers from very low vacuum (5 in Hg) and in spite of advancing the cam 2 degrees and opening the valve lash the vacuum remains low. Good idle is difficult to achieve and maintain and power brakes are also a bit of a problem.
For you guys who run the Duntov 30/30 what kind of idle vacuum do you have and do you have your cam installed straight up or advanced? If advance how many degrees?
