I stated in my original post I cleaned screen and blew out pump filter. I completely tore pump assembly down. Issue definitely isn't a dirty filter. You're right tho pump pressure could vary from bike on stand and bike under load. I'm ordering stick coils and a pump and starting there.
Not trying to be rude, but it seems like you don't know how these pumps work. The pre-pump sock/screen is indeed easy to clean, but the post pump filter is sealed into the plastic housing and is nearly impossible to remove and clean (if you've somehow done this I'd love to see pictures). Blowing air through it will not clean it... it will just move the restriction around. Flow testing a pump assembly at pressure will tell the tale, and I recommend you do that; it's not particularly difficult.
Second, free revving it on the stand is not "under load". Under load is 2nd gear or higher, 100% throttle, above 10K rpm or so.... trust me when I say there is a LOT more fuel demand there than in neutral on the stand. If you do not have a way to display or log fuel pressure "under load", an AFR readout (again) 'under load" will go lean if the pump is having a hard time (IE, fuel pressure dropping). They can drop pressure from a faulty pump, clogged filter, kink in a fuel line, or a drop in voltage to the pump.... but all of those will show the dropping fuel pressure under load symptom.
If you have stable pressure under load and it still gets lean up top, then you have an injector problem... It's really that simple. But none of these tests can be performed on the stand, you have to have accurate measurement under load. If fuel pressure and AFR's are acceptable and there is no misfire present (but it's still down on power), then you have a dynamic compression issue... which could be anything from the throttle not opening all the way (to include the secondaries) to a hurt motor or flat cams.
And to back Gaz up here, I've been down this road with more than a few pumps, and they all have displayed the same set of symptoms you are describing.... but I've always used instruments to diagnose it (gauges and logging) rather than just throwing parts at it. An AFR gauge and pressure testing rig will cot less in the long run, and you can move them from bike to bike throughout your fixing career.
EDIT: AFR's are indeed Air-to-fuel-ratios, and they require some sort of aftermarket gauge/measuring device to be monitored on a first gen..... they are typically called "wideband gauges" by the aftermarket. Most people in the business of testing/tuning/diagnosing repairs or engines have one or two laying around. :)