Porting 302's

I'm probably going to chance messing up a fresh valve job and pull them apart, clean them up a little at least. Like the Saturday afternoon car shows on tv that restore a rust bucket in a 1/2 hour show, the ones that want to "test 1 modification at a time" idea, I'm just asking the way I did, to try and see what each thing I want to do will help in the way I want to help this engine improve, but in actuality I'm gonna do the cam and intake swap at the same time as I swap the heads. Just curious how much each part I do, adds to or (? Hopefully not!) takes away from the current configuration, without actually having to the things apart 3-4 times and install1 part at a time while taking the last part installed back out, to break it down and see what I'm curious about.
I know that as long as the overall package is an improvement vs how things currently are, that's the main thing/
Engine in question is in a '78 b body sport fury, 56k original mile car. Currently 2.71 rear.
I've talked about what I'm thinking about doing to this car on here before. Cruises great at speed, just want a little bit more oomph than it currently has, in getting there without having to have it winding out a gazillion rpm once it's there so I don't have the feeling I'm gonna get run over, in getting out in traffic. Other than that one thing, I'm pretty happy with how this engine runs as it is. I have 2 possible cams here I'd like to use (one of), and 4 possible 4 bbl carbs here that are ready to bolt on. Thinking of the melling SPD25 which is a stock replacement 360 cam. Other choice is a comp 260. Carbs are 2-TQ (demon sizzler tweaked) a 500 AFB or a 625 AFB. Intake will be a performer (not airgap or RPM cuz that's what I have). And the 302 heads.