GT40 timing confusion

I was pretty sure I had the timing correct on my engine until reading Kens response on another thread.   I had never checked the GT40 manual as such since all the pertinent info was printed on the original engine cover.   But when Ken referenced the engine manuals page I was strangely drawn to check it out.

So Imagine my surprise when the timing information in the manual didn't seem to match what was printed on the engine cover!     From the manual:



And the factory engine cover:




So which is it??   Spout out, engine at IDLE   and set at 5 deg btdc ...
... or is it at 2000 rpm, as the engine cover suggests? .
OR am I just really confused and not catching something obvious   

I see. Well, it still is a bit confusing - or odd - that they specifically indicate @2000 rpm.   I've just never seen timing spec's at anything other than idle. But then I'm not nearly as worldly and edjemukated as you Ken