To get more stroke out of a regular Ford, Chevy, or Mopar engine, you can buy a crank from a larger engine and install it, like on a Chevy 383, or you can buy a new crank with a longer stroke. Since the 401 is the largest engine AMC offers, it also already has the crank with the longest stock stroke. The solution is to take material off of the rod journal to increase the distance of the rod centerline to the crank centerline and therefore add stroke. Adding stroke adds cubic inches. Here is the math: bore x bore x stroke x .7853 x 8= CID. As you can see, any addition to the bore or stroke also adds cubic inches. Bigger is better!