ls3 rocker arm stands have three different types that are available on the market; two of these types are flange type and keyed type and one type is tapered style with a hex socket driver with a copper coated nut. The flange type screw is used to connect two parts together and it has a tapered head on one end and a flange on the other end that is used to keep the two parts from moving once they are connected. The keyed type screws are used for attaching parts together that have a small hole in the middle and threads on the top and bottom of the part that are to be attached to the screw. https://www.totalperformance.net.au/DRP-LS7-PEDESTAL-LS3-WITH-LS7-VALVES-CONVERSION-ROCKER-ARM-PEDESTAL-STANDS-FOR-BOLT-DOWN-NON-ADJUSTABLE-OEM-ROCKERS