Well yes and no. The correct balancer is specific to the ‘65 260. Any balancer from a 64- 69 289 or 302 will fit and work.
Mostly no.
The balancers used on the various 260, 289 and 302 applications from 1964 - 69 all share the same pulley mounting capabilities and imbalance properties.
Visually they differ greatly. Some are heavier and some are lighter.
There is only one correct balancer for your application but there are many that will function just fine.
The wrong balancer greatly increases wear on engine internals, and at highway operating speeds, will cause vibrations.
Get the right one.
Jim