These replacement cylinders have fine grain centrifugal cast ductile steel liners. The High Density of the liner material will improve the liner and piston live drastically. Unlike others these liners are securely cast into the aluminum cylinders. This is a more expensive but much better way of making cylinders. The cast-in liners have a much better heat transfer than pressed-in liners, resulting in a cooler and smoother running engine. Due to the variety in pistons that can be used with these cylinders we have honed them to a few thousands undersize. This leaves the possibility to hone the cylinders to the tolerances needed for the pistons used. Cylinders are sold each and available in natural aluminum or black wrinkle finish.