Classic Parts of America sells a formed hose Part # 82-125 that is 1 1/2" on one end and 1 3/4" on the other end. It is sold to be used when installing a later engine with a newer style water pump (55 -62 pumps have a 1 3/4 inch connection) to an older radiator (47-54 rads have a 1 1/2 inch outlet). If you turn it around you should be able to install the 1 1/2' end on your 54 water pump and the 1 3/4" end on the aluminum rad. For the upper hose you could replace your 1 1/4 inch upper thermostat housing with a 1 1/2 inch housing from a later (55-62) engine and use a hose for 55-62 six cylinder.
