360 Tune Up

Hi Guys. Reopening this thread because it's been pretty informative for what I am trying to do.
After about 700 miles on my fresh 5.9 Magnum build I figured I would do some fine tuning.
It 's a .030 mild 218/226, air gap, 600cfm with headers. Stock electronic ignition. Has a 904 and 3.55's.
Initial timing I have been running was at around 16 degrees at 650 rpm. No issues.
Started my tuning and it appears my advance timing is coming in really fast.
Measured with dist vacuum disconnected and plugged. engine warm.
After build:
650 rpm. 16 deg
1000. 20
1500. 27
2000. 34 full advance

Yesterday I drove the car and adjusted distributor seat of the pants for best performance and measured again.
650. 25 deg
1000. 27
1500. 32
2000. 39
2200. 40 maxed

I must admit that I am no expert at ignition timing and usually set it and then adjust to what feels right and leave it.
I do have a vacuum gauge and set carb mixture at highest reading. Any thoughts on what I am seeing and how best
to set this up for best overall performance for street/highway/twisties?