360 a miss

I have a dead miss that occurs through the whole rpm range. Not as noticeable at wot but still there. I thought vacuum and changed intake gaskets and visually inspected valvetrain and intake. All looked good.

Here is the engine specs.
360 .030 over bore.
Flat top pistons with slight dish
stock bottom end with windage tray
Double roller chain w/ tensioner kit
Comp cams .488/ .498 lift 274 / 286 .006 duration
Comp cams 867-16 anti pump up lifters
Comp cam cupped push rods
273 adjustable rockers
340 Valve springs damped
360 J heads w/ 2.02 valves
Weiand dual plane intake
Holley 600 Double pump w/ 2 corner idle 70 primary jets, 80 secondary, 6.5 power valve
msd 6al box
Mopar perf dist
8mm wires accel
Autolite plugs.
rotor and cap good
Stock fuel pump at 9-14 psi New reading is 4-6 psi.

Compression on my antique comp gauge is.
1 = 100
2 = 90
3 = 100
4 = 90
5 = 90
6 = 100
7 = 85
8 = 85
The engine was cooling off as I progressed.

I also ran a cranking vacuum check which the needle fluttered between 0 and 5 indicating a leak? I also ran a running vacuum at 2000 rpm. This showed a consistent drift between 19 an 18.5. While doing this I unplugged each wire and took note of a drop of 18 hg on every one with the engine changing sound on everyone. Not really indicating which cyl is a miss.

Short of tearing down to the shortblock I don't have an idea. Anyone else