I know that the conventional wisdom for 4003 bass necks says that they should be straight, but just how straight is "straight" for this bass?

When I capo fret 1 and press the E string down at fret 20 (a common procedure for checking relief), I measure 0.010" from string bottom to the top of fret 8 using my automotive gages. When I do the same procedure for the G string, I can't even get the 0.0015" underneath.

I suspect the E-side truss rod could use some tightening and that the G-side truss rod could use some loosening, but I don't know how much. What should I be aiming for in pursuit of the recommended straightness?

You should be aiming for whatever you like, what works best for your own playing style. There is no 1 ideal setup.

Agreed, and I generally prefer as little relief as possible without intolerable feet noise. Given my preference for straight-as-possible, RIC qualitative recommendations, and some internet research I've done, I'm going to shoot for about 0.002" or 0.003" clearance at fret 8 and tweak from there if need be. Problem now is that my G-side truss rod is unresponsive, but that's a topic for another thread.

That should have been "fret" noise, not "feet" noise.

I figured that, but still, just don't move your feet.

When the Ric is thumpin´out some heavy funky licks you´re supposed to move your feet.

Right on, Micky.