[Healeys] The AEC960 Healey 3000 Cylinder Head spark plug seat and timing issue

[healeyguy at aol.com]

Just went out to the garage to check accessible heads. The AEC 960 seems to
match what has been stated previously.  The electrode on a Champion 12Y plug
(3/4 inch thread, 1 inch including electrode) is pretty much flush with the
projected dome of the combustion chamber. The other head is a Westlake marked
AEC 666 (there is a reason this head didn't last long) that was used on the
integral intake 100-SIX. Admittedly the combustion chamber is different shape
with an interesting half moon cutout around the plug but the same plug does
project another 0.25 inch into the chamber.
Aloha
Perry