Got another one out but last 3 will spin freely and move up and down a bit but get stuck near the top. Might make up a puller or am tempted to leave them in as they, and all the others, look in good nick.
All rollers and sliders also look in good condition - nothing missing or split and still seem shiny and move freely. See pic:
Cam lobes also all look good - clean and shiny and when turning with my finger on them i can feel no flat spots or issues. Hard to get pic that's worth a damn but here's an effort of a couple of them:
In short - seems to me like what we thought might have been the issue doesn't appear to have been. Unless I'm missing something (easily possible...) then all the components look to be good and should be doing their job fine. Will give everything a good clean up anyway ready to replace at some stage.
While I was there I took a closer look at the pistons - all move smoothly and bores look clean and no scores or scrapes. Piston 1 though does have some pitting amongst the carbon - see pic - but don't think that's any cause for concern is it??
Got a spring compressor coming today or tomorrow so plan to remove the valves next since i'm checking everything else. But am beginning to think I'm not going to find anything that could have caused the noise in the top end and maybe i'll need to go back underneath and look at the shells after all.
If any of you think i've missed something do shout!
On the plus side with no pressure to get it running on a deadline, and this all being new to me, and it not raining, it's actually been an enjoyable strip down so far with almost all going to plan. Which is rare and i've probably jinxed it now...