Speed grade and voltages for TigerSHARC Z060 vs Z050

I have managed to secure a quantity of the higher speed ADSP-TS201SABPZ060 instead of ADSP-TS201SABPZ050 as was originally specified for a design.

In the datasheet it states the Z060 supports up to 600MHz instead of 500MHz but the data sheet implies some different voltages for Z060 at 600MHz versus Z050 at 500MHz.

These are:

Vdd changes from 1.05V to 1.2V.

Vdd_DRAM changes from1.5V to 1.6V


Question: Does the Z060 still needs the higher voltages if it’s not actually being operated above 500MHz?  The datasheet is unclear in this situation.

I would prefer not to have to increase the supplies if it’s unnecessary (3-6 resistor value changes).