Ok, cool. I think we're on the same page now. First off cubes definately equal power. So yes, same parts, same tune and same car, your 406 is going to make it to the end of the 1/4 faster, no question. The problem with these motors in particular is that people get an education about engines through hear-say. They take something somebody told them at the track one day as gospel and it really needs to stop when we get into a technical conversation. I'm definately willing to accept anything people can prove to me about a 400 chevy, and I think this thread is useful to get rid of myths. THere's a reason that chevy never used their biggest cid smallblock motor for performance. THe reason they probably didn't want to use the longer stroke is more probably block design. With a stroke that long you'd have to use a different, weaker cam, and clearance the block a ton. BTW a larger journal accomplishes the same task. .200 of metal is not going to make or break a crank, it simply moves the center of the rotating assembly down a little bit more so you dont hit the cam.
Siamesed walls still bother me. They allow heat to build up in the engine and pass from one bore to the next. I think chevy was worried about them too, so they never punshed the motor too much.