Yep i'll be replacing the valve stem oil seals and valve caps while the heads off - had a look at the pistons and they are in very good condition with cross hatch honing very visible in the bores. There aren't any wear ridges in the bores either - so it all looks good. The pitting looks to be bad but the head hasn't been skimmed before so i'm hoping that the head skim will remove it. Might give the valves a quick lap too when i remove the springs to change the seals. If it does turn out that the head is scrap i've still got the engine that it had in before so i could use the head off that - but won't know until its been tested.................