Big Block Edelbrock limitations.

If the real goal is 550-575hp, from a docile, streetable, relatively low maintenance, pump gas 440....... it will be easier to get there with TF240’s.
And if you got a fair price for your used RPM’s....... probably cheaper in the long run.

Could you get to that power level with unported RPM’s?
Sure..... with more compression and a bigger cam than what you may find is enjoyable in a street car.

10:1 446 with RPM heads, smallish solid cam, SD, 850DP, headers,....... with proper machine work........that’s an honest 500hp build(made 500hp on the dyno).
I built that exact combo in 2005, it went in a 3900lb 71 Charger R/T with a 10” converter and 4.10’s.......... ran 11.70’s.

For 550-575hp, swap to the TF heads, go up a little bit on the cam, 10.5-10.75cr...... should put you right where you want to be.

The most I have seen personally out of BBM RPM heads was 665hp.
That was a basic bracket race, high CR 493, with an easy on parts roller cam, heads ported to flow 300.