Quote: any chance manifold or booster leak is causing vacuum fluctuations? I chased more than one holley surge/idle issue caused by problems in those two components.
Not that I can tell, the only other test I could do is to take it on one of the back roads and cap off the booster post and see if it makes a difference. Have sprayed the intake a number times with no signs of a leak, it could be internal but it shows no signs of sucking oil.
