So since I replaced my heads and cam I have had some idle issues. The idle was very inconsistent. I think I finally figured it out to be the PCV valve. Since I a pulling less vacuum than I was before the valve was not closing at idle when I would try to idle below 850. I was using a pcv valve with essentially the same configuration as stock 289 valve but with the right angle elbow. It 13 inches of vacuum it would rattle and buzz like crazy. I tried the fram fv181 (stock for boss 302)which is supposed to have low vacuum closing threshold. It was the same as my other one. I did run a fixed orifice valve which was better, but give no backfire protection, and doesn't adjust for idle, , cruise, acceleration, or WOT. I think I found one that seems to fit the bill. It's a PCV for a Ford 2.3 four cylinder. It's staying closed at idle. I will post back if there are any issues as far as driving go. I know this PCV is not made for the engine and is not tailored to the performance specifications. I eventually want to change over to one of the M/E Wagner adjustable units. Anyone have experience with one?