40 degrees initial!

I'd first confirm, as other noted, your damper marks are correct.

You never said what your CR is...that would be good to know.

Nothing wrong with 40 degrees at idle as long as you back off of it as soon as you start to load the engine.

In the late 90's I had a 526" Hemi with an 8-71, Speed-Pro EFI, 8:1 CR, and .420 lobe roller cam. By the time I had the tuning done, the spark map would be at 52 degrees advanced during cruise conditions. It ran super-smooth on the highway, like it had 24 cylinders. Of course, the timing would back off as soon as load increased. I had set up the car to include a knock sensor* but in the end it ran so well I didn't bother.

The real problem in all this is not the advance but the primitive ways in which we control it (on a non-computerized system). But you can at least try to emulate what a PCM would do.

*Tell the PCM to take all or most of its timing commands from the knock sensor.....run the advance right up to the point of knock