Post away! I pretty much did all my talk'n in the video, lol. I'll lay a flat edge on the bottom of the head, but other than that, nope. Virtually, this is how I've checked my valve guides and valves over a lot of years. No issues to date.
It's like people are smoking pot and they're totally paranoid or something.. just say one or two things on the internet and all of a sudden you're checking like you're a scared rabbit...
I can't tell how much first timer hackery I did to those 360 heads I put on that 318.. so many mismatched valves and springs and retainers.. I wound that thing up to the moon and it never did anything but said do it again...