People will go on endlessly over the cid and bore difference between a 318 and 340/360 but an extra 23-43 cid plus a 1/4" bore waste of time. Funny how no replacement for displacement/bore ends at 360/408.
If you don't mind a square engine you could be running around with 496 instead of 408.
I have a square engine in my truck. The Ford 400. A lot of people wrongly claim they are junk, but in reality they're one of Ford's best engines. What's not to love about a square tall deck 400 cube Cleveland? It's a torque monster.