Going to a longer crank arm will change your ability to spin at high RPMS. You might not notice much of a difference at low RPMs but when you get above 90RPMs you'll feel it....all of that will require you to basically rebuild your pedal stroke from the hips.

That being said it's a biomechanic thing. Without knowing your inseam length, bike fit/setup, experience who can say.

Pedal strike will probably be the biggest issue.