Is Compression influenced by rockers off?

I'm sure a lot of you have read about my low compression problems that i've posted before. Some answered, thanks. After talking to a stangnetter the other night, we thought the low compression might be caused by timing being messed up, thus keeping valves open when they should be closed. 1 cyc. was good (160) and 7 were bad...110, 90, 40's, etc. He said to test it, check a cyc. w/ low compression and pull the rockers off for that cyc. and test again. He said if it's out of time, the compression should increase because the absense of a rocker would allow the valves to close. Is this a valid assumption? I did this and before w/ rocker comp. was 90 and after w/ rockers removed, it was like 70, so i'm not sure what to think. Any ideas?

First of all, thanks for the responses. I get the feeling most people don't read previous responces, Smock, lol, so that's prob. the reason for the same responses.

I'm sorry, yes I know ignition timing fires the plugs, I did mean mechanical timing as in timing chain, etc. I figured maybe the timing chain slipped or something, but a shop checked it and it looked to be fine. No broken teeth on the gears; I put the front half back on at home instead of having them do it. The car does not run at all. I bought it, drove it for like 3 weeks, less than 300 miles and it quit running one day and hasn't ran since June. It is supercharged, i'll throw my sig up after this post. The motor was supposed to be rebuilt with like 5000 miles on it, but i'm not positive of that...no documentation. It does have one good cyc (160 lbs) and I think that's cyc. 4....the others are not all within 10% of each other. I pretty much figured either bad rings, gaskets or valves. The shop said there is NO possibility of a bad or broken valve in that car, but i'm not sure why. Head gaskets would most likely give a white smoke correct? And what are the chances of blowing both head gaskets at once? Also, I noticed no anti-freeze in the oil. If you throw gas in the throttle body and crank it, it will try to start, but can't quite do it. Before it quit running, it stalled at lights and stuff possibly due to the blower w/ no bypass valve, but i'm not sure. Also, it was blowing black smoke on takeoff=rings, right? This is gonna cost a fortune!

Thanks smock. I didn't know cast iron heads were bad? I think I did the oil in cyc compression test, but i honestly can't remember because i've done a few compression checks at different times just messing around and this process has been months; i'll do it again. I've never pulled a head, but I want to and just see. If the weather were better here, i'd for sure do it now since i'm on Christmas break, but hopefully I can get it done anyway. I'm definately gonna get a bypass valve. Thanks for all your help....really appreciate it man.