Mr Gasket Timing Cover Bolts for Small & Big Block Chevy MG6090Mr Gasket Timing Cover Bolts for Small & Big Block Chevy MG6090 6090 The special smaller than standard hex head is ideal for tight spaces. Because of the hex flange head design, it will not fall back into the socket wrench, allowing for easier installation. Special under head serrations prevent loosening and the wide flange head distributes uniform clamping pressure for an Ultra gasket seal. Bolts are zinc plated, Grade 5.