Here's the 360 in My 71 Cuda. My car had the numbers matching 340 in it and I beat on it pretty hard. So I built a 360 La 4" stroke 408. I Put my 340 on a stand in my garage. Once you use a new rotating assy. crank,rods,pistons, you can have it internally balanced so you don't have to worry about the external balance deal. Now I have no guilt beating the hell out of it and it pulls way harder.