Signs of bad head gasket? 99 OHV

[specialized7]

Hey guys, well upon adding oil to my 99 OHV sport (it uses half quart every 5000k)i noticed coolant looking scum on the oil fill cap, my coolant is a bit low but nothing crazy.
my coolant overflow however looked a bit dirty, but my rad looks clean?
Iv been searching and everything leads to a head gasket going out?

A year ago when i bought the truck i had the lower intake gasket blow out on me and i had that fixed for the cost of 500.
This time im going to rip into it myself while i have the confidence built up, but what im asking is do you guys think the headgasket is the cause?
Iv noticed a rough idle once in a while but nothing as bad as the 3 dead plugs i had.
Thoughts?

 

[briwayjones]

How far do you usually drive to work or wherever after you start it up? If it's not very far then the scum could be condensation under the cap unless it's real bad from the engine not getting fully warmed up.

 

[specialized7]

i drive 500kms a week to work but not anymore as of yesterday ill be working in the city.
i changed the oil and checked my antifreeze, it hasent gone down at all so maybe i will be ok for a while.