Part# HV8-VCStdSpcr6-Zn - Holden V8 valve cover high tensile bolt Kit for use with our AussieSpeed 6mm billet valve cover spacers for roller rocker clearance when fitted to Holden 253 or 308 V8 engines. This zinc coated hex socket caps bolt kit comes complete with 12 x bolts, washers and spring washers to enable you to bolt pressed tin style valve covers to a 308 Holden when using our billet 6 mm [1/2 inch] spacers. For example, standard Holden or aftermarket pressed tin & pressed alloy style tappet covers. The length of the bolts allows enough height for two cork or rubber felpro style or similar gaskets to be used with the spacer and the standard 3/16 inch thick spreader plates under the bolt head. This bolt kit would also suit a 253 or 308 with Alloy valve covers that have a 1/4 inch thick flange around them and not using spreader plates.