Well, unless you try and make power like a certain class racer does, a better flowing port is always a help. IDK if I would port the X heads and even more so after the described treatment.
Im also not sure what the cost of the CNC program is for your guy or if the heads need to be rebuilt but I’ll just leave that cost out since there probably pretty good if there in use now with not an extreme amount of miles or abuse.
Im just saying here, not so much suggesting this route for you, but it if was a build from scratch, I’d look at these
Shocker 185 Mopar CNC (Sold in Pairs) - PROMAXX Performance Products
or the trick flows (though a little more expensive on head and suggest rocker gear) which at the moment, are not in stock at trick flow. Maybe somewhere else. Point being is the fatter flow curve down low to the .500 lift area. I myself would use a 1.6 rocker on the MP .528 cam to regain the lift lost by lash and geometry angles.
As a side note, an opinion, if you don’t already have the MP mechanical .528, I would look for a different cam with very similar duration (though I might use a slightly less duration myself) and more lift. Don’t get me wrong. The MP grind is a good street & bracket cam.
If you already have it, stab it and run the socks out of it!