There was a test many years ago comparing the big blocks of all the makes( I believe it was HotRod that did it), it actually had a very surprising winner out of the bunch, and only a few of you probably have witnessed this engine. The 455 Buick was quite the monster in the GSX back in it's day. It was never a real popular car so it never got much publicity, and the engine never got tossed in anything light like a corvette, mustang, camaro, or E body, so it never showed any awsome 1/4 mile times in a 4000lb car.
Lumping engines as best in a size displacement is also extremely broad. a 426 street hemi is far different then the ones of famed lore. Same thing when people think of 427 chevys, they think of the L88's (over 500), L-71's (435), L-72's (rated 425, but early rated at 450), and the ilk, rather then the run of the mill L-36 (390) Gross numbers obviously (these are in just the corvette line, and impalas and the like and the range gets even bigger).
327 chevy is an even wider ranger starting with 200hp or less 2bbls and going up to the 65 corvettes fueli 365hp. Saying the 350 is a shadow of the 327 is also foolish, take a ride in a 70 LT1 (370hp) and tell me the 350 lost something.
302 ford runs the same gammet from low performance 2bbls to cleveland headed boss 302's. So if you want to pull up best engines of yester year you'll have to be specific as of your choices.
BigRat