440 power gains/ aluminum head advantages?

My answer isn’t really an answer…….

Before making any recommendations I’d suggest quantifying what you have.
In other words…….. time for some track results so you can put a number on it.

Imo, it’s got too much gear in it now, so I wouldn’t be expecting big mph out of it in the 1/4.

Does it have headers on it?
A decent intake manifold?

If it’s a “no” to either of those, that’s where I’d start.

If you haven’t done one yet, I’d do a cranking compression test.