For what it's worth,
My 71' was tuned by a Guru in Texas. He set the timing "Static".
I returned to Maryland with the car. I proceed to make myself familiar with the car. I wanted to check the timing to see where it was set so I would know for future reference. I tried to check it several ways with my old Craftsman timing light. That did'nt go too well. A TR Club member told me I needed a Timing Light with "Advance". He said "Set it like you drive it". Meaning to raise the RPMs to about 2500 with all the hoses, and stuff connected.
So, off to Sears I go.
Got a new Craftsman Light with Advance.
Fire up the car, I pull the trigger on the light. I reach accross the engine and manually raise the rpms until the timing mark stabilized(reached full advance). I turned the advance dial on the timing light until the timing mark on the engine was at 0°, with the rpms keeping things at full advance the whole time.
(BTW: I noticed the timing mark was noticably larger at 0°. My guess is that someone enlarged the mark at 0° to make it easier to see.)
anyways,
So now I've got the mark at 0° at full advance. Guess where the Advance Dial on the timing light is set now????
40°
That's where the timing was set when I had it tuned(by a TR Guru), and that's where I keep it.
So with that expierence under my belt, maybe SCGuy is onto something with that 40° figure.