Even with proper Corbin tool, can be a bit challenging on some of the hoses.

On my E Body 440, find on the thermostat housing clamp was better to first place the clamp on the housing, then slip the hose into position, then use the tool to expand the clamp over the hose into its proper position. Some tools will not expand clamp enough to get the clamp over the ridge on the housing.

Be careful at the heater end, as these fittings are prone to break off from heater if you have to wrestle too hard to get the hose on and the clamp in position. A shot of dishwashing soap or Wd 40 can help in sliding a brand new hose into position.

Be certain to position them such that you do not end up slicing your forearm or wrist while working on the engine. These pointy edges can be quite sharp and to catch your wrist is something you won't soon forget. I have not yet had the pleasure but every time I look at these clamps keeps me wary.