The Stovebolt Site Forums The Shop Area Engine Shop '61 Apache heater hose placement

My heater core has developed a small leak, so I'm preparing to remove it for repair. The shop manual has a bold-face caution regarding hose placement:

CAUTION: Note the hose placement. Use extreme care not to reverse their position. The 3/4" hose from the water pump must go to the upper heater core pipe; the 5/8" hose from the thermostat housing to the lower heater core pipe.

The hose connections at the core are according to the caution; 3/4" at top, and 5/8" at bottom. The problem is that my thermostat housing has a 3/4" fitting, and the water pump a 5/8" fitting, with the hoses connected according to those sizes. The 1961 shop manual supplement has no information regarding the heater hoses.

I've tried Google, and searching Stovebolt, but found no information...so my question to the 'Brain Trust' is this: Does hose placement really matter (what's the onus for having them reversed?), and if so, is it possible just to switch the fittings between the thermostat housing and the pump?

Thanks!

-Kevin