Jeep Compression Test Results...Bad Piston Rings?

[Andrew R]

I've done a lot of work on Jeeps, and I know them pretty well, so I got a dirt cheap 99 Jeep Cherokee 4.0L straight 6 with a blown head gasket. White smoke out the back, water in the oil, shaky idle...the usual. So I replaced the gasket in a day or two, not bad at all, heads didn't look too bad. After I finished, started right up : no white smoke anymore, no water and oil mixing, however the idle was still shaky. The rpms stayed constant around 800, but the engine was shaking quite a bit, causing the interior to feel like a washing machine. Anyway, did a compression test. Cylinder 1 - 30psi Cylinder 2 - 110psi Cylinder 3 - 0psi Cylinder 4 - 120psi Cylinder 5 - 120psi Cylinder 6 - 125psi.......I said 'crap, not good'. I did the test like 5 times to make sure. Then i poured a little bit of oil into cylinder 3 because 0psi to me was a little TOO low. Then i did the compression test again and got 120psi out of cylinder 3. So just from pouring about a cup of oil into the cylinder, my psi went from 0 to 120. Now the car DOES start and run...if the rpms are above 1500, you can't even tell there is a shake. I know its most likely that the guy blew not only the head gasket, but the piston rings too....I'm just trying to confirm that this diagnosis sounds right and that theres nothing else easier that it could be before I go tearing down the engine. Also, do I need to get the block honed before installing the new rings? Thanks for your help.