Speaking from experience, 8 studs and an alloy head on the KH / KHA is not a recipe for gasket leaks. On the later engines, there is a 9th stud between the cylinders but on the alloy cylinders at least, this stud gets stripped in the cylinder by over enthusiastic tightening. I believe its main function is to assist in removing the cylinder from the crankcases by means of the long bolts.
I am on about 13,000 miles on the current head gasket which has seen the head removed and replaced 2 or 3 times.
36 4G, 37 VH, 53 ex ISDT KHA (project), 54 KH(A), Healey 1000/4 (project)
Former Machine Registrar & Archivist, General Secretary and Single Spares Organiser.