I've had a 360 in my Duster swapped to a .030" 413 now putting a 383 in it after a lifter cup cracked and did the glitter thing. After having a big block I can't go back to a small block.
I remember a magazine article years ago where they did a compression comparison on a 440 using super thick gaskets but can't remember the exact ratio they compared but I think it was around 60hp from lowest to highest.