Thumbnail Filmstrip of Crank Support without Hub - RCD Extended Big Block Chevy Crank Support for use with 1V Pulley Images
RCD's Big Block Chevy Extended Crank Support
Allows for a 1V Accessory pulley
You have to use the RCD Extended Crank Hub and Bolt with this unit.
If you want to use a 6 Bolt Blower Style Balancer with this you can if you get this piece :