Yeah, I used new torque-to-yield headbolts. The replacement heads
were exchange ones from the machine shop, which performed perfectly all
last summer and this one.
I had overheated the car badly last summer which caused one valve
guide to drop far enough to hold a valve open; upon disassembly I found
several other guides almost to the same point and thus replaced both
heads. My initial check before starting that procedure indicated 150
psi on all cyls except one which had zero. The dead cyl currently has
150 and I didn't bother to check any others--all I know is I pull the
plugwire off and the rpms don't change.
I, too, found the appearance of the plugs to be "not what I expected."
I run 10% ethanol (gasohol) in it most of the time, but this last time I
put premium in it just grasping for clues what might change the way it
was running. This might account for the coating on plugs(?) which are
otherwise fairly new. I'm usually a little leery of buying premium in
any case since it doesn't sell anywhere near as quickly as the other so
you don't know how old it is... plus the prices now probably make it so
nobody buys it at all.