How difficult is this? If I do it, and it turns out I need new piston rings too, have I wasted my time by doing something that's gonna have to be re-done by a mechanic/shop if the rings are replaced? Better to have shop do it all?

 

Like I said before, do a leak down test. That will give you some insight as to what is worn out. Otherwise, you are just hunting.

 

Yes, do the leak down test if you haven't yet.

However, valve stem seals do wear out, it's not an uncommon thing. I just had mine replaced when my head was rebuilt and the machinist had to remove all of the valve springs to access the seals. He did this with the head off the car, I don't know if there is a way to do it while its on the car.

If you take the head to a machine shop, they're likely to find more things that should be replaced than just the seals. I had my whole head rebuilt except for the valve springs which were still good.

 

I just did mine. It's a cheap fix, but without the right valve spring compressor, can be a PITA. If you want to eliminate that as a suspicion, it's cheap.

I used 1/2" rope stuffed in each cylinder to keep the valves closed. Once you do one, you will get the hang of it. It just takes some time.
I would recommend using a magnet to grab the keepers once you compress the valve spring. There are plenty of "How-to's" on the process. Depending on your heads, you will have to reset your valve lash after you are done, since each rocker arm comes off.

 

Did this on mine a few years back. I put a fitting in the spark plug hole then hooked the air compresser to it. Pressurizing the cylinder will hold the valves up in place, then its just a matter of getting the springs off. Fairly easy just takes some time

 

The seals are cheap but the job is involved. The fact is that if you drop a valve the heads gotta come off to get it out. I recently paid 300 to have mine done because I was scared, the unfamiliar terrifies me at my age. It was well worth it, I had started using a lot of oil and now not a drop.
Unless you're a brave guy I think you should take it to someone you trust, have the leakdown test done, and if the rings are good get a price for replacing the seals. Sometimes it pays to let a pro do it.

 

I'm inclined to agree with you. At least that way if something is screwed up I have someone else to fall back on besides me!

 

I don't know how you change piston rings, but if you have to have the head off to do it, then why not replace the seals when it's off?

(remember the leak down test before you do anything)

 

will do.......thanks....

 

and when you use and air compressor to pressurize the cylinder, if it'a a manual trans, make sure it's in neutral or it can run over your foot. I, (ahem), heard of that one...