7.3 confusion reigns

[woelks]

Here's one for ya. (edit) 1997 with 150,000 miles. Truck missing on one cylinder, fights and stumbles to rev above 2000 with major smoke- then at over ~3200 rpm smooths out nicely.
Ran diagnostics- indicated Injector circuit contribution fault on 1,2,5. Replaced some damaged injector/ glow plug wiring, one VC gasket, and three indicated injectors.
Flashed her up to find no change. Still misses and rough between 2-3000rpm.
Ran diagnostics to find the program does not indicate consistent problem. It is shows no problem on the buzz test, then on the first round Injector circuit contribution fault on 1,5,8 (1 and 5 are newly replaced injectors) next round 5 and 8, next round 1, next round 1,5,8.
Fuel pressure is 55lbs at idle- do not know pressure above idle.
When running at high rpm we noticed mist or smoke blowing out in a jet from between the firewall and right head inwards toward the pedestal. Only saw this once momentarily but there is a little smoke down there; the down pipe has a shiny residue on it in this area.
Any ideas where to go from here?