You have a boost gauge that shows vac on the car don't you?
If so whats the vac reading at idle?
Did it. No leaks found....... still random misfiring. CRAP!let it idle, spray carb cleaner at all the vac lines and sensors, if the idle jumps up, you found a leak area.
vacuum seems very steady.Was the vacuum steady or was it bouncy? I've dealt with this before...and I have pictures of the problem I found...and they aren't pretty.
Seized roller on a lifter that wiped out the cam...sent metal all through the engine...we hoped we got it all flushed but ended up having to replace the engine shortly thereafter.