I am hoping to recover some of my top end without killing my part throttle performance . I just feel like my build should support more than 6200 rpm .
The eratic fuel distribution lead me to think opening/ cleaning up the plenum would help .
Spacer or no? Try a 7/16 thick spacer if you haven't.
If you work the flange/runner roof transition and at some point it goes backwards instead of forwards in #'s..try a thicker spacer.
I see where people like the intake as rough as as 10 grit...like an old asphalt driveway pitted up. Everything's different, I like both because I dont have a have a dyno to show me which is a game changer and the numbers are there. Numbers dont always mean what you think,but it's a measured increase...and it's better than going on blindly grinding.
I round the the roofs.. I dont lay them back into the runners, but I've also aimed for a not to so high target... but some people do.
The advice you've been given is good.
