Engine Condition

I need some advice here. The engine in the car (200) has been rebuilt sometime in its life, the pistons are stamped .030, but its not doing too good:

Low vacuum

Mucho blow-by (blows out the breather and dipstick yet burns very little oil, does'nt smoke at all)

One cylinder seems to be missing and I cant trace the problem back to anything in the ignition or carb.

Low compression (compression tester is suspect)

I'm wondering if the head is so far gone that it is causing some of these symptoms? When I got the car the valve seals were non-existent and the valves looked pretty rough. They cleaned up nice but felt a little loose when I put them back in. If the valves and guides are shot could they cause these symptoms? It still runs right up to 85 mph so I'm thinking something wierd is going on. Thanks

Ron

8) it sounds like the rings are stuck. run some marvel mystery oil through the system to see if you can free them up.

Tried that already. If the rings were stuck it would smoke like a SOB and it does'nt. Maybe the oil is crap and it won't smoke!