RCD spool spacer .375" I.D. x .610" O.D. x 2.00" thick SBC crank hub. Made from billet alum. this spacer allows a racer to mount a crank trigger bracket off the front of the engine block and get the proper spacing so the timing pointer and crank trigger pick up line up with the degree ring.
Takes two spacers to mount crank trigger bracket and spool spacers are sold separate.