I am replacing the front crank seal on a 1968 4.2 XK engine and purchased the updated Teflon seal. However the new spacer that you also need to install does not have the woodruff key channel. I can remove the outer key to install the spacer but the inner key holds the timing chain drive gear in place and a quarter of an inch of this key protrudes out from the gear restricting the spacer fittingby anjennings - Jaguar E-Type Forum