The repair will depend on the noise.
AF Moderator is correct in that rebuilding is the proper course of action. However, is this a cost effective solution? In what condition is the rest of your vehicle?
My experience has been that lots of noise is caused by dirty oil, or low oil.
Here's what I'd do.
1) Buy some "oil cleaner" (turns out it is usually just kerosene) to loosen up everything in your engine. DON'T RUN THE ENGINE VERY LONG since if there really is worn out equipment in there, the distillates will reduce oil pressure even more.
2) Drain the oil, and expect sludge.
3) Refill oil with Mobil 1 or some other synthetic oil.
4) Pray for miracles.
At one point I had what I thought was a broken lifter, clang was terrible. Using the steps above, the noise was resolved. That was 200,000 miles ago, so it was more than likely a stuck valve.
Be sure to report back to the forum what happens with your vehicle!
--Mark
http://www.marksatterfield.com