Yet another rough idle LT1 thread

This has been driving me nuts for a while, I am almost out of ideas. I have a 95 Caprice wagon with 80k on the engine (so I am told when I bought it). At idle there is a noticable roughness to the engine, you can feel it in the steering wheel at times too. Heres what I have done so far to attempt to fix the problem:

New EGR (kept throwing a code, ripped diaphragm)
New Delco plugs and wires
Replaced intake gaskets because of an oil leak. Replaced cracked PCB elbow and vacuum line. New throttle body gasket installed, throttle body bypass mod done
New exhaust header gaskets and bolts
New delphi O2 sensors (one threw a lean bank code)
New water pump (leaking from weep hole), replaced opti and wp seals.
Swapped injectors with 8 known good ones, new O-rings
Fuel pressure is 40 primed, 35-40 while running
I checked the vac lines, none appear cracked, even tried pulling one of the intake one at a time and covered the port, no change.
Home plate deleted.

Theres no codes thrown, and I probably would just ignore the idle, but my roadmaster with more miles on it idles so smooth you cant tell its running.
I keep looking at the opti now, when I got the WP out I pulled the opti and cleaned it. It was covered in oil, and even had a little in the harness connector. The vent does work properly. Also, when I took the throttle body apart, the gasket under the plastic cover was really stretched. Its the rubber kind. I ordered a new one and havent gotten it in yet. Thats all that comes to mind right now, any ideas guys?