Airbubba:
A lot of 757 and 767 systems are similar but many, especially hydraulics, are significantly different. The two planes were literally designed by two different groups at the same company. Or, so they tell me...
Boeing has used tandem design teams for decades. The B-29 and B-50 e.g. The two teams "leapfrogged" each other, with only general exterior similarity. In the case of 757/767, they coordinated on general cockpit design and handling qualities, but little else.