Tappet Guide. See #10 in second illustration. Tappet guide replacement, must be installed by a machine shop and once fitted to the cylinder head the tappet guide will need to be reamed to the tappet diameter. FITS 1969-1987 XJ6 4.2. We also stongly suggest installing the tappet guide holddown KIT part# NBM0001. (C7262)
