On the 80 Series 3FE and 1FZ engines, all of the heater hoses are secured by a spring steel clamp that is tightened at the factory using a cotter pin and tool to lock it into place. These are intended as single use clamps. If you still have these clamps in place then it is highly likely that they, and the hose, has never been changed. Its less likely that the engine was serviced by a Toyota dealership so its good to assume they need to be changed.
This is the replacement 25mm clamp for all 3/4" heater hoses found on all Land Cruisers up to 1997.
OEM part no: 96112-10250
MADE in USA