Top End Miss

Its in the valve train IMO.If not the valve lash ,and it has solids ,maybe its spring bind at high rpm .Have you checked that out ? You got me thinking when you said you up'ed the springs /pressure and the miss went up another 200 rpm ...

yes i set the installed height on every valve... so no binding... besides this only started with the gear change, i changed springs in trying to fix it... made it better but not gone... lash is 16/20

Does it miss, or just nose over?

miss... feels like a couple of small pot holes... you know that surge feeling i mean...

Not sure if this will apply to your case just thowing it out there. i had a similar problem with my car, at the top end of the track it would stop pulling and sometimes regain just before the end but not always..after checking everything I could think of..turns out it was my fuel delivery system, mainly the filter I had between the tank and pump...last week at the track it did it and this time I looked down at my fuel pressure gauge...it was zero.....checked the plugs in the pit, very lean, I was running out of fuel when I needed it most, not because of the pump but the filter had debri in it....just a thought.

has a new filter and made sure the pump had no junk in the screen on install but cant hurt to change filters...