Alan is correct when he says bow and stern shape will make difference.
I've taken Millbury up and down the C & H several time over the 35yrs I've owned her. She is exactly 60' not including the rudder (measured with plumb line and laser). She has very fine bows and elliptical counter, which is an advantage, but her bows are deep in the water, which is a disadvantage as they will not go over the cill at low water level (the reason why some boat have to come down some locks backwards).
Took Millbury up the C & H this year with James Woolcock (Marquis 54') and shared all but two locks, once Millbury was behind one gate Marquis came in beside her, it wasn't tight after the gates were closed and the locks were filled at a normal pace.
The two locks that we decided it would be prudent to single out at was the top one and one about 6 down from the top, the latter has a wide walkway mounted on the bottom gates which is over the lock chamber when the gates are closed. The top one is definitely the shortest, we got Millbury lying on one side with the gate closed, but the counter was touching the bottom gate and with modern gate building practice of having bolts sticking out of all the fitting on the inside, we thought it best to move her bow to the centre of curved cill giving more room at the counter end.