As radicalz stated above,when you change the bore and stroke of the 454,you need to plan out which cam profile you are going to use.Many years ago,I took the ls6 motor out of my 1970 el camino and increased it to 496''.Alot of changes were needed,but with that stroke increase,the torque of the motor really put me back in the seat.Take your time and plan it .It will be worth it.FISHMANJOE