Horse power will be close to the same except for the diff in c.i. and rpm's.
The 350 & 400 use same crank(if i remember right)
The 455 will make more torque due to more leverage. And at a lower rpm. Great street motors.
Another advantage of turning a 3.25 down to 3.00 is theres less fiction and wieght. It turns faster like a 400