I know what your after and Here it is....You can walk past a 440 on the stand and fart and it'll make big power...
BUT! You gotta know how to fart..This does NOT mean huge tunnel Rams and twin carb's that have the street manners of a top fuel car...
You could step up, get yerself a stroker kit, go for broke @ 500 Inches, and make some real power..
A REALLISTIC approach to HP for the STREET out of a STREETABLE 440 nowadays when Imports with HUGE turbo's are puttin' down 700 HP, is between 450-550 HP IF BUILT CORRECTLY...This means knowing the CC of your heads, Static Compression ratio, Piston to deck height, camshaft overlap, Aluminum VS iron heads, Size of Valves, Size of cam (Lift and Duration @ .050), etc....