Have just rebuilt my engine and have now got a large port head but after rebuilding had an oil leak on the head gasket at the cylinder 1 back oil gallery so though maybe might have got a bit of ****e in there so thought id give it another go, although the head had just been skimmed but got dropped in transit so thought id get this checked as a precaution and it had less than half a thou run out on it
Although the block was still in the car, rather than remove thought the best method was to use a machined bar across the center of the block and run a DTI along it (i know its not ideal but dont fancy stripping everything down just to clock it) the results were very consistant and the max differential i got was 3.5 thou (less than 0.1mm) across the whole block an put it back together and it is leaking in exactly tht same place
a friend of mine has said to try wellseal on the gasket as i used no sealantl but am not a fan of trying to mask a problem and really didn't think that little amount of run off was that crucial??
your opinions and views would be much appricaited