The last time the valve cover was off the engine was when I painted it but that was a year ago. It was idling normal my idle problem did not start until just recently. I plan on taking the intake off in the near future to combat those vacuum line. I am going to replace them with steal line with as little rubber tube coupling them together to eliminate the worry of any vacuum leak coming from there and of course the hassel of removing the intake just to get the line.
I will investigate the oil filler cap idea.