FUN,
ERA has this comparison on their web site:
http://www.erareplicas.com/427/img/3pro_front.gif
Also worth noting that the intake system (manifold plus carb/EFI throttle body) has a large variance in the 385 series.
For example, the Torker II is the shortest intake - all the rest are higher. I use a Torker II.
Also FWIW the Holley throttle body is at least an inch, if not 1-1/2" shorter than a Holley carb if memory serves correctly. I use this also.
That said, I still have a vertically sorta ugly scoop on my E-M to accommodate a reasonable size air cleaner. Not sure I want to lose a bunch of HP by using too small a filter area.
YMMV!
Tom