Onkyo TX-SR603X & RT5000

It will work but watch out for clipping.

You can surely fry your tweeters with clipping.

From Wikipedia:

Overview of clipping
When an amplifier is pushed to create a signal with more power than it can support, it will amplify the signal only up to its maximum capacity, at which point the signal will be amplified no further. As the signal simply "cuts" or "clips" at the maximum capacity of the amplifier, the signal is said to be "clipping." The extra signal which is beyond the capability of the amplifier is simply cut off, resulting in a distorted waveform.

Effects of clipping
In power amplifiers, the signal from an amplifier operating in clipping has two characteristics that could damage a connected loudspeaker:

Because the clipped waveform has more area underneath it than the smaller unclipped waveform, the amplifier produces more power. This extra power can cause damage to any part of the loudspeaker, including the woofer, tweeter, or crossover, via overheating or overexcursion.
In the frequency domain, clipping produces strong harmonics in the high-frequency range. Extra high-frequency weighting of a signal is more likely to damage a tweeter than a signal that was not clipped. However most loudspeakers are designed to handle signals with abundant high frequencies, like cymbal crashes, which have a greater high-pitch frequency weighting than amplifier clipping could produce. Therefore damage attributable to this characteristic is rare.
Other effects of clipping include:

When applied to a musical signal, the clipping may prevent a note from decaying in a normal amount of time. This can cause rapidly played notes to blend together.
Music which is clipped experiences amplitude compression, whereby all notes begin to sound equally loud as loud notes are be clipped to the same output level as softer notes.