However, you have to consider that taking core class credit advances you into much harder classes, choosing to not take the credit for core classes in e.g. engineering might help you protect your freshman GPA if you need it to enter into your speciality. Taking credit though, might get you out of weed out classes (which can damn your GPA anyway LOL). It is really a question you want to pose in terms of your major, and your target school. It can be a double edged sword in tough majors in tough schools.