Not neccesarily. If the stem seals were gone as well, then yes, you'd expect to see oil smoke when you stab it, particularly if it's been idling a while.
But it is possible for the valve guides to go without taking out the seals straight away.
The reason I asked if it was gas was because I don't usually see a lot of Falcon heads develop this problem, unless they're on gas. Oh well :)
To me, it sounds from your description like valve guides. That's all I can think of that produces those symptoms, anyway
Proud TQE Operator and President of SEFAG - the Society for the Elimination of Ford Automatic Gearboxes
Pacemaker headers + 2.5" exhaust
EF Fairmont interior
Lowered King springs
5 speed manual
Newest mod: EF Ghia wiring loom and dash