60 degree rotors vs 120 degree rotors

In a blown alcohol 14-71 roots combination is a 120 degree rotor more efficient throughout the power band over a 60 degree rotor? Assuming you were using a K-11 or "F" style rotor with a pie opening style case in both setups is the 60 degree rotor more efficient at lower engine speed (below 8000 RPM) and lower overdrive (below 35%)? As an example, nostalgia style alcohol funny car with a hemi using a centrifugal clutch leaving at about 2200 RPM and shifting at 8000 RPM.

Most of the nostalgia classes require a 6-71 with 60 degree rotors. These things have become pretty efficient over the last few years with the pie outlets and larger setback rotors.

I haven't paid much attention to modern 14-71 top fuel blowers lately but have they gone to the smaller bottom outlets or are they still full open bottoms?

Thanks

Greg