Edelbrocks are $500 and the Stealths are $600 (Stealths require more valve work, retainers and locks). Guides are checked and honed if necessary, spring pocket depths are checked with head surface, performance valve job, valves set to the same depth, installed heights are set, all valve springs are tested, heads cc'd, ports are blended, heads are surface milled and flows are tested before and after. Everything is cleaned, lubed, assembled and bagged ready to install.