Trick Flow 440 heads, The Real Deal?

No insult taken. Yes blocks are stressed at that level, but the BBM is a good design and can take it. Its not so much the "power" as it is the piston speed, rod angle and the tune. Girdles do help, Main studs, 4 bolt main caps do as well. Those Race Hemis could make a Lot of power and the basic design is the same, deep shirt, tall deck, rather high cam location. Is there something better than a factory block? Yup, but they are few and far between these days.