The current pulley is hollow. It's a March 33% under driven with dual grooves. My DMI bracket has all of the supplied spacers plus a few washers to get the alternator where it is. I no longer need the second groove of this pulley (ditched the P-Steering) and someone (or me) will probably need this for another project. I'm not going to attempt to modify the pulley nor further space out the alternator. I don't mind buying a new pulley. Just wanted to know what others are using with this balancer. Doty pulley ordered yesterday. Thanks!