Will taking an AP class (say AP Calculus) helps you develop skills that will translate to a higher ACT score? Will the better teacher in the AP class make a difference when you take that ACT? Getting a B in an AP class is the same as a B in a remedial class as far as BYU is concerned with the GPA, so if you are going to possibly take a hit with a lower grade in a more difficult class, you better hope there's a positive somewhere in the equation. And a better chance at the ACT/SAT test might be that positive.