Comparing old to new is a bit moot, New motors have either port or dirct chamber fuel injection, the manifold and port only have to move AIR and not carry fuel in suspension. Put a carb manifold on a modern hemi in a 4400 pound car nd watch the torque plummet at low/medium piston speeds.

The cleveland in smaller 2V form still needed a long skinny intake manifold runner just ot make decent torque, and the 4V was a bit soft on the bottom end unless you had steep gears, you basically had a smallblock with a 427 Chevy size intake port , they used to sell port stuffer sheetmetal plates to pick up the velocity in the Cleveland heads which blocked the lower third of the port....but Clevelands still make really stout 408+ " short rod stroker motors.