Spark plug tube update?

It's probably just floating around on the old style longer tube then. I replaced the rocker box seals at the same time so that maybe cured it? I'll remove the spark plug tube donut at the next valve adjustment then. What is the intention of the floating valve cover?

I think it was just an attempt to improve the sealing and prevent the tube coming off with the cover. In damp climates, especially in places where they salt the roads, the tubes tend to rust into the rocker cover and get pulled out of the head when the cover is lifted. By deleting the long tube and replacing it with the short one that just goes between head and rocker carrier/cambox it will not be disturbed until rebuild time and will therefore be a lot less liable to leak. Sealing the cover to the top of the casting of the cambox is probably less problematic than relying on the o-ring and corrosion prone tube.

Just a guess....