Yes you are correct the 400 block was a stronger block and could stand more abuse, 400 were good if you build them right, like you can have a 400 block machined to have 455 crank in it. The only reason I went with a 455 was that my dad knows a guy that built one about 10 years ago for a 77 firebird, well long story short he wrecked the car before the motor was dropped in it and has a 750 hp racing motor in his basement. I talked to him and he told me if I wanted it bring him 500 dollars yes 500, and the motor would be mine then all I would need to do is build a transmission and get a rearend and gears that would handle the hp. I don't have much money to build the car with just run into good deals and wait and wait til I find the right things. But I am slightly building a 400 for my 78 T/A that were putting together.
