I'd still suspect ignition parts. New coil doesn't necessarily mean good, and is it wired correctly? You can hook them up backward which will still fire but low voltage, which usually becomes an issue at higher RPM. What's the brand of the ignition box? Orange boxes are notorious for higher rpm misses. I realize only the low level MP boxes are actually orange, but the standard replacement boxes of any brand can have the same issue. When I use stock electronic ignition I use the Mopar chrome boxes. Even in other brands the premium boxes are usually chrome, while the lower level ones are painted.
And what Lustle said. Check the timing and the timing advance, could be the initial is off or it's not advancing. Could also be that if you're running a stock distributor and have advanced the initial past 12* or so that you've getting too much advance at higher rpms and you need to limit the advance.
And rule out fuel flow, although I trust new fuel system parts a lot more than I trust new ignition parts. New fuel system stuff tends to be good, new ignition parts are probably only a little better than 50/50 in my experience.
