Maybe 2 more things need to be considered - Manifold design and weber/bike carbs inner flow paths.

Bike carbs on an evenly spaced 4 cylinder require manifolds with less turns or changes for fuel mix
to hit the sides and bike carbs dont use chokes to create turbulence which differs from slides.
Yet even on an A series, slightly offset inlets due to 2/3 exhausts ports doesnt create an issue
but on longer L series engines it could be more of an issue compared to webers.

In the above 2 points on an A series, bike carbs seem to good/better paths to inlet ports provided
they are well matched and better go smaller than too large in most cases.

Dave still waiting for a sound file :)