Concerned Engine Issues UPDATE

[chrismoore701]

Posted this last week. Changed oil and only drained about 2 1/2 qts. I did some investigation and this is what I found

Compression is 135-155 on all cylinders
I have attached a pic of all the plugs pulled out top one is #1, bottom is #8
Plugs were autolite 25 gapped about 30-35
Total timing is about 32 degrees
New plugs installed are Delco plugs- R45TS gapped at 40
One thing I noticed is the rear filler cap on the valve cover is very loose
It just slides into the valve cover
The breather in the front has a gromit pushed into the valve cover and the breather pushes into that.
My builder drilled the hole in the valve cover and never noticed how loose this cap was
Any thing I can do? try to get one that may fit better?
Anything I could wrap around the cap?
I noticed oil residue in this area
Could the hotter plugs gapped at 40 give me more power? Feels like it.