If you are talking about the main cooling tubes under the car....
They should be in multiple pieces in case you ever need to remove them while the engine is installed.
I suggest you put "bungs" or valves in them (at the lowest point) to assist in draining the coolant, so it doesn't make such a huge mess.
Here's what I did.
5357 - Cooling Tube Bungs
Also, this isn't directly related, but do the self-bleeding radiator mod. George describes it in This thread - scroll down past the thermostat, and look at the line drawing.
Self bleeding Cooling System
Rocky
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