I noticed that the earlier models with 5/16" and 3/8" bolts originally were 25flbs for both dia bolts and 26flbs for nuts and 18 ftlbs for barrel nuts. in a later service sheet 118-2 they have changed too
28-30 for the bolts 31/32 for the nuts and 18/20 for the barrel nuts.
was this increase to reduce cylinder head blowing and can the bolts nuts take the extra torque?
I'm always very nervous when torquing things down.
I too would be interested to hear an answer to this enquiry. My 1962 A50 has developed a slight cylinder head gasket weep despite having the cylinder head and barrel faces gently skimmed and despite having annealed the head gasket. I have retorqued the head to the original workshop manual figures.