Stalls with electrical loads

OK, long day yesterday with this thing, first off the fuel pump started leaking so had to replace that before doing anything else. Drove it around in hopes that may have contributed but of course no. So I removed the carb and here is what the T-Slot looked like:

After playing with the secondary adjustment this is where it ended up on the primaries:

I was able to go out about 1/4 turn more on mixture settings at idle. Car is about 90% where I want it. Stalling with accessories on does not seem to happen now. I also put degree tape on the balancer to more accurately check initial, total and vacuum advance. Car liked 16 initial with 36 total but detonation occurred at the upper end of the rev range. May go up a tad in Jet size on the primaries and see how she does. Settled back at 14 initital, 34 total for now and it does not rattle. Really odd how my other car did not mind either carb that sat on it but the 350SBC does have flat tops, zero decked block, running 9:5 CR to my mopars 8:00 with same cam specs: 270/280 .423/.414 cam. Cams only spec out 204/214 at .050 lift. Pretty mild cams considering the vacuum they pull at idle. Looks like the low compression engines need more throttle to idle and it just exposed too much T-slot.

Also, the voltage at coil in neutral, no accessories was about 7.5 volts. It's been a while since I had one I couldn't figure out on my own, thank you everybody for taking the time to post and help out. Big thanx to AJ for bringing up the T-slot issue.