Need help with diagnosis!!!

My 351 C 4V motor has a fluttering sound comming out of the tailpipe which coincides with rought running of motor at idle and other speeds. It will even shake sometimes. I say fluttering sound because it is not just a 1 cyl. missing sound, and mostly on the drivers side tail pipe. Here'e what I have done so far. Changed plugs, old ones looked good. Took out Pertronics module and put points back. Changed coil.I have Ford Motorsport 9mm wires with a wide top dist cap. I changed intake manifold gasket.
I am trying to confirm either multiple burnt exhoust valves or blown head gasket between cyls or possible weak or broken valve springs. Vacuum reading is about 14 and fairly steady but will lower to about 12 or 13 which seems to coincide with the rough idle and fluttering sound out the tailpipes.
I might have to take it to someone with a scope to eliminate electrical problem.
Can someone give me thier expert opinion?
Thanks.

<font size=-1>[ This Message was edited by: Rancho Lenny on 8/17/02 9:00am ]</font>

I'd do the easy tests first like a compression test.If you've got two low ones together you can suspect a blown gasket between the two.Just plain low compression might indicate your valves aren't sealing.The vaccum gauge should flutter if you have broken valve springs(I'm assuming you've got the double springs or else your valve would be hanging in the cylinder.

Just checked compression today, here are the results.
#1-212 #2-214
#3-215 #4-210
#5-210 #6-210
#7-210 #8-210
So it looks like rings are good (confirmed with vac. guage going from 2-24 inches when opening throttle), and no evidence of blown head gasket on adjacent cyls.
Vac. guage shows no evidence of burnt or sticky valves.
I guess I will have to have someone put a scope on it to rule out spark-ignition problems.
Suppose I had intermittent lifter problems causing inconsistent valve action. Could this be a valid problem?
Back when I was adjusting the valve lash I noticed that when adjusting preload, some valve springs would compress after 0 lash rather than the lifter side of push rod going down a little. What do you think?
If it's not ignition what else could it be?

I had problems like that once. It turned out to be a cracked holley base plate.

I used carb spray to find the problem.

<font size=-1>[ This Message was edited by: SCOTT on 8/17/02 10:26am ]</font>

BTW, the cyls on the drivers side are numbered (from the front) 5,6,7,&amp;8.
[addsig]

this might sound silly, but double check your firing order...just incase?

Here's the Deal:
Sounds like you have intake valves which at stuck slightly open all the time, sucking in air/blowing air out intermittently. This is because when you adjusted lash, some valves are open: If your spring has moved during lash settings, your valve is open; when fired up, your lifter will inflate, and thus multiply the amount that your valve was open when you set the lash (the spring moved to start with..and has mved even more because the lifter filled with oil). Recheck your lash, and if your springs still move , then you either need shorter pushrods, or an adjustable valvetrain! This is only my opinion. I have the same engine, with this valvetrain problem: Solution: Crane conversion kit /w energizer rockers.