Hose Clamps

I have been very happy with the spring style clamps, once i got the correct sizes.
Not one drop of coolant

Look at this post. I posted hose sizes and clamp sizes and part numbers

I imagine early A 273 would be the same as later 273. Hoses might be a bit different shape.

Dale's Cuda Shop wire hose clamps not the correct size? - 1967 Dart 273