Your engine is right inline with your mods....like everyone else says, the "Performer" intake is made for 273/318's. A Edelbrock RPM AirGap is the intake you want.
Theoretically, the edelbrock 800cfm carb is capable, but I would get a Holley 750-3310 vac. secondary, and jet it accordingly to get 13.5-14:1 at cruise/idle, and 11.8-12.5 under WOT.
Then, I would get rid of that Orange Box, and upgrade to a MSD, or Jacobs Electronics Ignition.
13.50 - 13.80 @ 105ish is right inline with 275hp at the wheels in a 3200+ lb car....sorry, its the math...it never lies.
The stuff I just told you would probably yield another 100hp at the wheels properly tuned and extend your rpm range another couple hundred RPM.