Flatlander Racing
Keith Craft
Edelbrock FE Cylinder heads
Stage II - 330 cfm/250 cfm $2295
Stage III - 375 cfm/280 cfm $2995
Avenger Cylinder Heads
The heads shown for Keith Craft & Avenger are both 427-size valves...as SCOBRAC mentioned, you don't want these on your 428. I listed them both so you can contact them and get info on 2.09" intake ported heads. Flatlander's chart lists max flow at .700 lift, which isn't all that helpful if you're valve is opening .560". As a matter of fact, full lift isn't the best way to compare how a head will perform on your engine; it's more of an advertising gimmic. I'm sure you can get more info from Flatlander and others such as flow at various valve lifts. Another option, as mentioned by rblong, is to buy the heads then have them ported by someone locally. However, you usually aren't going to get heads that flow as well as those from Keith or another large operation that first finds out what makes a certain head flow well, then is able to machine those profiles onto the heads they sell with CNC equipment. Don't forget to check out ported Blue Thunder heads as well...Keith has done some work on these, although I'm not sure if he's producing them yet.
After saying all that, your best bet is to call Keith Craft, Flatlander, Avenger and others mentioned to get the info that applies to your build.
Good Luck,
Dan