I have a 1965 Impala which pulls hard to the right when braking. The brakes have been checked and are fine and I have also repacked the wheel bearings. What should I check next ?

A car of that age could have a bad rubber brake line that doesn't let the pressure through. Try a new pair. Also after driving the car, feel each wheel to see if one brakes is doing more work than the others. They should all be around the same temperature for each axle.

Igmf this car has drums up front like nost do make sure they are adjusted correctly. Jack up the front and have someone hit the brakes as you spin a wheel and see if the ly engage at the same time. Seems like either the driver side front needs adjusted tighter ir isnt working at all. Also check all steering linkage and ball joints and bushings.

If this car has drums up front like most do make sure they are adjusted correctly. Jack up the front and have someone hit the brakes as you spin a wheel and see if they engage at the same time. Seems like either the driver side front needs adjusted tighter or isnt working at all. Also check all steering linkage and ball joints and bushings.

if you have drum brakes check the wheel cylinder to see if it's frozen . If disc check caliper and slides or a clogged up brake hose. The pull is from one side not working properly

I owned a '65 Impala in 1967. Chevy had a recall in 1967 specifically for this problem that was caused by a failure of the idler arm. You would want to take the car to an alignment shop and have it checked out.