*** IN STOCK SHIPS TODAY *** For the racer that is wanting to install a LS RCD crank hub on a LS-7 engine, make sure to pick up this crank hub spacer to make the installation complete. Made from billet heat treated steel the spacer measures .850" thick, 1.40" I.D. and 1.850" O.D. Spacer is black oxide plated for corrosion protection.