The root of the problem is indeed the liners- they are not fixed at the top (o ring at bottom) and consequently move around. There is very little protrusion, so the movement is worse than it might be which "rubs" against the h/g and causes it to blow. They are also an iron construction, so dont expand as much or as quickly as the rest of the aluminium engine which doesnt help.
Very careful assembly and correct torque-ing / dial gauging of the head bolts can help, but if you have a K, then assume the h/g will fail at some point(s).
Tim..