I see a lot of modern engines, such as the new Hemi or the LS-series, getting custom big-bore sleeves. Can a similar process be done to, say, a flathead Ford? Everyone I ask about this says you can't ...

Ever felt like adding some more punch to your H-D Sportster or Buell XB and thought things are either hard to come by or not safe enough? Well, they're not, not with the all-new Zipper's Big bore ...