I think most M60 series were sold or scrapped.
US has @2500 M1 series assigned to the 20 divisions of the Active Army and the National Guard, or in prepositioned storage around the world. And another 3,700 in reserve. Unlike the M60, the M1 chassis was designed to be at least somewhat modular and upgradable, so the maintenance and upgrade potential is always there.
Thats an enormous number of first line tanks.
Trouble with the M-1 is the turbine engine. Bringing the Ukrainian engineers up to speed during wartime would be problematic. I am pretty sure a lot of the M-60’s are sitting in a pasture somewhere.