a roller block is a 87 and up block that has the provisions to add a roller cam(86 and older don’t). the provisions arel the longer lifter bores, and holes for the cam retainer plate and lifter retainer. they all started with hydraulic cams, and eventually made the switch over to roller cams. roller lifter should only be used on roller cams and hydraulic lifter s and hydrulic cam. you can use your hydraulic cam but you need to use your hydraulic lifters, not the roller lifters. talk to me tommorow about this.