What's the easiest/cost efficient way to balance a gas warm air furnace system? Should I use dampers in the supply lines or will new adjustable registers do it? We have a 3 1/2 year old HE furnace with central air in a 2 story house built in 1890. About 1200 + - sq ft. Thanks

Should I use dampers in the supply lines

Yes

When try to adjust at the registers it may get noisy.