First time swapping edelbrock aluminum for 915 cast iron heads.

AJ/Forms
Much of what your saying is beyond what I understand. Engine building definitely isn’t my forte. I’m learning as I go along. Not to discount that I’ve learned a ton from this website. My original motor ran really strong with just basic 915’s, no porting or anything special, older mopar performance 284 duration 484 lift cam, KB pistons, 9.8 to 1 comp. Harland sharp roller rockers, Edelbrock Performer intake, speed demon 650 cfm, 4 speed trans. It dynoed at 340 rwhp about 380 rwt. I’m changing out the 915’s to edelbrock rpm performers with a bump in compression to about 10.2 to 1 with the mild porting and milling which reduced the size of the edelbrock chambers to 72cc from originally being 75cc. I don’t understand why the motor is going to fall flat with those chambers. I know that a lot depends on how quick the cam reaches maximal lift and how long the valves stay open and close but I don’t know the original specs on the original mopar performance b/rb cam. Keep in mind this motor ran great on 93 octane no pinging even on hot summer days. I think that was due to original comp being 9.8 to 1. Now I know aluminum heads can run higher compression before pre detonation so I though 10.2 to 1 should work great. Why would you want to run up to 11.2 to 1 compression with the edelbrock’s and risk pre detonation on pump gas? Is the 180 your referring to the optimal cylinder pressure? I’m changing out the carb to a 850 cfm race demon and please explain where I going wrong because I don’t see how the motor is going to fall flat? Can people please explain in layman’s terms?