Do you feel that you are taxing your NAD 753 to the point that you are clipping or running out of power? Do you play so loud that you feel you are not getting the full dynamic range the speakers can deliver?
There is very little point in switching something that is not broke. If I was you, just to answer the curiosity, I would try hooking up the M60's to the NAD370 (directly) with some source material that you know and like and listen. The problem is Psychoacoustics that you will hear what you think you want to hear. The reality is if you could properly blind test the two, you would be splitting hairs to hear any difference between the two units.
You will be making something far more difficult and adding in more complexity than is needed for a net result of probably ZERO. I'd say just don't bother.
Axiom: ADA1000, LFR1100, VP180, QS8, EP500, M3, M3comp
AudioSource: Amp One/A