great response all, much appreciated.
before diving in i'd like to reply to Artstream- burnstream sounds like a great place to get a new head gasket
hope to make it there someday
i've owned the vehicle just under six months and regularly drive to the zoo which has a wonderful rustic campground. we took a 400 mile round trip to the FL panhandle earlier this year and she performed great. rattled a few things loose on the inside but easy fixes. it was a flat run with no real hills to test the power under load, unless you count 4 fat people and a stocked fridge!
oil temperature ran steady around 200-220.
it does tick on the passengers side when cold, then goes away when it's warmed up, but doesn't tick after getting hot, i'll have to double check though. the oil didn't look milky, haven't got round to recycling it yet so will take a look after work today.
hopefully it's just the head gasket, might could find a shade tree and fix it myself. if it looks like i'm in too deep i'll call this guy down at the gmc shop whose done off ticket work for me before.
we're in the process of moving house, so camping and related tinkering has taken a back seat for now, but it gives me time to think out the process. the idea of full timing is becoming more and more attractive, so much junk to sift through!