Radiator hoses

Look closely at photos. The lower hose is fairly standard if you have the correct radiator and water pump. In early 273 those have 1.5"OD tubes and are on driver side (recall, later small-block are 1.75"OD outlets on passenger side). I used a later water-pump and radiator in my 1965 273, but not a wise choice (caused many issues). The upper hose depends a lot on if an AC compressor and whether factory or aftermarket. You may have to customize a hose. I wouldn't use those flex hoses. Many hot-rodders use the earlier F-150 upper hose since long with many bends and only $8. By cutting it and inserting an aluminum splice piece, they can orient the bends to fit most anything. Not terrible since that splice can incorporate a debris screen and/or ports for the temperature sensor and come cheap in purty colors on ebay. Small-block T-stat nipples come in various shapes, and may have varied if factory AC or not, and may have been changed if an after-market compressor. If you buy a new one, avoid chrome-plated ones which soon flake. I used a stainless one from ebay on my 273.