Bolt torque discussion

a couple of observations
on head lifting- on the turbo Rambler project we used German Bellevue washer/ 0 rings and the heads did dance around (I have no remembrance of where Barney got them)
on the SBC we used necked down bolts for the short ones so we could get same stretch as the long ones- these are still available

on the cracked heads are you using hard AN style washers with the bevel to spread the load?
in aluminum blocks we used a larger thread in the aluminum than on the nut end
bolts can be too stiff and thus loose clamp easier- you do need the spring/ stretch effect
using a grad 8 or better bolt in a light load where a 5 ws specified is almost sure to give you a too stiff/ hard bolt
to make a grade 8 work you have to torque it to grade 8 torque which just does not work on say valve bodies (warp)or water pumps (strip) etc-- use the correct bolt