In stock and ready to ship. This is a 420/500 to 520(518cc) conversion topend kit with standard size piston, rings, pin, clips, cylinder and gaskets. This 520 cylinder will fit all 420 and 2012+ 500 cases without any case cutting. These are all OE Honda parts in the Honda packaging. We strongly recommend a fuel tuner to correct the air/fuel ratio on the 420 and 500.
**No warranty expressed or implied due to the nature of this product.