Honestly mine didn't fit into my EVO 1/4 pounder without some "finesse." So expect some modifications.
They have changed the 1/4 pounder now so it fits a lot better.
I have the newer 1/4 pounder and I just dropped in my Powerplant. Not difficult at all compared to the stories I've heard with older bumper. It's a tight fit but no cutting or grinding required now