| Re: Worth fixing a head gasket and what damage does an engine take?
It sounds to me like you have a leaking valve seal. You're getting oil into your combustion chamber. Be sure to take your heads to a machine shop and have the heads overhauled. I have a place near me that does it for $60 a head.
Sometimes you can't tell which part of the head gasket is blown but you'll almost always see that one of the pistons is bad and probably needs new rings if not a new piston. So I would replace all the rings. You'll have to unbolt the rods for this so you may as well replace all the rod inserts. Buy some stuff called "Engine Assembly Lube". Put this on rod bearings, cylinder walls, and any other place that oil usually lubricates moving parts. This is used for lubrication during those critical moments when you start your engine and oil hasn't started circulating yet.
And here's the most important part: KEEP TRACK OF YOUR PARTS. Buy some small zip-lock bags. When you take out a set of bolts, put them into a bag, write what they are on a small piece of paper and put it into the bag. Do this religiously to everything you take off the engine -- every bolt, every bracket, every pipe, every tube, EVERYTHING.
Then another important part -- get a digital camera. If you don't have one, buy one. Consider this as part of the expense of overhauling an engine. Take pictures of EVERYTHING!! Open the hood, take some pictures. Disconnect the battery, take some pictures. Remove the altenator, take some pictures. No manual or descriptions can take the place of a picture. You will not be able to remember what you took off when or how. I speak from experience.
And of course, run some tests before you start to determine if it really is a blown head gasket.
Jim | 
