Set new engine up help?

get it running ,get out a vacume gague see what readings you have in gear and at idel.I like to see what reading I have in gear with foot on the brake.Lets say you have 9 inches than a 6.5 power valve is good to go.As a rule always drop down 2 points from what your reading is.Be sure to set timing up first and mixture screws.Me i love holleys easy to tune.So lets say your reading is 7.5 with a 6.5 witch is almost always in a holley than that power valve is now open causing an over rich mixture at idel.