Based on the original Signature Series Crankshafts offered by Lunati, this series is designed to withstand the extreme pressures encountered when using a blower (Roots-type supercharger). With all of the original features of the Signature Series, these Signature Blower Crankshafts have .125" radii on the rods and mains, as well as dual keyways, larger nose bolt threads and enlarged flexplate flange threads. The #1 rod journal is also undrilled in order to provide extra strength on the front of the crankshaft.