Head and cam selection help for 440

It means they’re ported on a cnc machining center.

Imo, changing “nothing but the heads” is not going to totally transform the way your car runs.

Figure out what the budget is, and then determine how much of a hp improvement you expect to see from that investment.
Then see if the goals seem realistic for the proposed changes.

It’s unlikely your current combo has “maxed out” the current heads.
As such, it’s unlikely you’ll see the full potential gain out of the new parts.

For example, based on flow numbers alone, a set of TF240’s have the potential to make about 200hp more than the stock heads.
But...... swapping only your stock 452 heads for a set of TF240’s, and changing nothing else....... won’t get you anywhere even close to a 200hp gain(with a mild combo like yours).

The other approach is...... figure out how much power you want to make, and then see if that goal is within the reach of your budget.