This is a modern 12v blower motor that is a direct replacement for 1955 and 1956 Buicks.
 
I have been using this in my 1956 Century with great results. it works with your original controls. aside from looking a little more modern, it is a direct replacement.
 
When wiring this blower, please know that the orange wire is ground and black wire is power. I know that is unusual but that is the correct way to wire it.
 
Some1955 Buicks require slight filing to oval out the two mounting holes. Most 1956 Buicks require no modification.