Power steering and AC bracketry quandary

On a good note, what a fine selection they had, everything I wanted.
Got the heater hoses run. Odd little setup. Both holes at the motor (head/water pump) are 3/8" ID. But on the 4-port heater valve (FSM shows 2-port BTW), one is 3/8" and the other is 5/16". So I used 5/16" hose and forced it onto the 3/8" hole at the head rather than have a loose fit. But now it looks bloated out there and a possible failure point way down the road.
5/16? That seems mighty small. You sure not 5/8?