They will be plenty of power but IMO still a poor choice. The first issue is the voltage. When looking up the specs, they give a torque rating at 4.8 volts. This means you are limited to the voltage of a 4 cell nicad or nickel metal battery. The better battery choice is 6.6V LiFe battery. Main reason for LiFe is a much lighter battery for the same capacity but the voltage stays consistent longer. However when they drop off, it’s a fast drop off. Not really an issue as a 1400 mah battery will easily last 8 flights with a 6 servo setup.

The next consideration is size and weight. There really is no reason to use full sized servos in a .60 size plane these days. There are mini servos available from multiple sources that are plenty strong. My favorite is the a MKS HV 69. The mini servos will save you even more weight but make your install less crowded. Of course if you already have the Futaba servos, you can still run the LiFe battery and run a regulator between the switch and RX. My favorite is the Castle Creations BEC that is 5.5V output.