We're near that point as well, Charles...
...but from our experience with the -6, as late as possible. Get as much wiring done as you can but then the dash has to be in place, if only clecoed, to wire switches, radios, and so on.
One very nice option is the pitot/static system that Avery sells with simple push-in pull out connectors, no wrenches needed.
We're also going to finish the panel with radio stack, Dual screens and switches on the bench before putting it in the airplane, where it can be powered up, tested, tweaked and so on. Then all the radios/xpdr/audio panel, etc. can be slid out to reduce weight.
Regards,