help with top end miss

hay guys at top end i have a miss or fuel loss or something....it sound like fuel but i tured the reg. up to 7psi the other day ...i have a msd 6al mopar dist. locked out and moros 8mm wire set new cap and rotor ...what do most of you as for fuel pres. its just at top end about 6800/7000...thanks
I am running 7 psi fuel pressure on my 408 ,and mine has that miss your describing at 6100 .I would be curious to hear sum suggestions on this topic as well...