Usually thoughts of Cold War tank technology make me think of laser rangefinders, composite/reactive armor, smoothbore guns, and complex fire control systems.
However, many of the tanks coming immediately after the war still used RHA and rifled guns (e.g. T-55, Chieftain, M60) and simple rangefinders. In principle were these tanks using technology available in WW2 with newer designs? Or were there less visible technological advances that would have made these tanks impossible to manufacture with the technology of the 1940s?
While perhaps not immediately after the war one early post-war development was the oscillating turret. In the 1950's tanks began to have NBC protection added and overpressure systems as well. During the war a Frenchman invented hydropneumatic suspension that was later added to some tanks. Fused silica in the mid 1950's to deal with HEAT which lead to composite armour. Autoloaders did exist during world war 2 but I believe they were not used in any service tanks until after the war. I am reasonably certain that world war 2 tanks didn't use coincidence range finders, though the navy did so. they were added to some tanks along with a simple ballistic computer in the 1950's.
Really there wasn't a lot spurring on tank production between the end of the war and the beginning of the cold war. Most of the tanks introduced after the war were simply improvements on existing technology, tanks with more armour, sturdier engines and bigger guns.
Oddly the ranging machine gun, a coaxial gun that fired special tracers to help lay the main gun was not used in in WWII. It is a fairly straight forward idea that was adopted in postwar British tanks.
Chieftain and M60 are not immediately post WWII tanks being from 1966 and 1960 respectively.
You're thinking of the Centurion and M46 (I hope)
Because the two tanks you listed are far and away superior to the tanks more than a decade younger.