Hei conversion troubleshooting

I replaced the valve stem seals this morning, and took the car on a 300 mile round trip tuning drive in the 95 degree heat.

I also swapped the step up springs under the rods for the strongest/richest ones (bare metal) it had the middle ones installed. Seemed like it helped my condition a little. Still, with the vacuum advance can plugged in the engine surges slightly and runs rough at light throttle cruising, especially up gentle hills. Unplug the vac advance, runs much better.

I have progressively retarded the initial timing trying to get rid of the bad running condition but I’m at the point now where the car is hard to start.

Now I am wondering if it is somehow ignition related. I replaced the coil, because my original was showing a secondary resistance of only 6.5 K, and the car seemed to run better. Now it seems to be the same. Bad condenser? Or perhaps I fried the new coil in the heat? I am using a ballast resistor.

So here we are, I either have a timing issue, an ignition issue or a fuel issue.
cruising 70-90 mph, car got 11.6mpg with vac advance and 10.6 with it unhooked. 95 degree heat, 87 octane.

I will pull the plugs tonight once the car has cooled off and post a picture of them. And check what initial timing I finally ended up with after retarding multiple times.