Any explanation aside from Head gasket?
 

Nope
May not be leaking into the cylinders, but if you see bubbles there, it's definately leaking out.

Yeah, I guess I need to start researching Head Gasket Jobs.

Basic hand tools, torque wrench, angle gage($15)
$85 Lucky8 head gasket kit(has everything), oil change, few gallons of coolant, black rtv silicone sealant, and a saturday to do it.
$50 coil packs and a set of plug wires wouldn't be a bad idea either, since you'll be taking them out anyway.
Takes some time, but not a hard job.
Go for it.

I'm giving Lucky 8 a call.

Yep, looks like that head gasket has $hit the bed. :cry:

And like Six said, it's not that bad of a job...just plan ahead with parts and give yourself enough time to get the job done.
Call some machine shops early to get an estimate on lead time and cost for resurfacing the cylinder heads.
Lastly, a good bottle of Tequila goes a long way to guarantee an accurate head gasket replacement! :cheers:

Thanks for the encouragement guys. Feeling a bit overwhelmed, but am going to start reading through the job and printing out the instructions.

I appreciate the encouragement, and I have all the tools I need, so time to get to work.

Resurfacing the heads is always a good idea.
But, if your truck hasn't overheated, and otherwise runs good, I would check them with a straight edge.
If they're flat, I would just put them back on.
But, if you can get a machine shop to resurface them, it's cheap insurance.

And, as tempermental as these engines are, now's also a good time for a $90 set of lifters.

The engine only has 28,000 on it. I will look into lifters though.