Regarding the heads, that engine is not yet assembled yet but I ended up using the right side head from the pair pictured above. My machine shop took off 0.015-0.020 (not angle milled) to clean up the gasket surface which brought the combustion chambers into the 67-70cc range. I plan to get them all in the 69-70cc range for this 276ci motor. I'm not sure if these heads had been cut before, but even with this light cut I had less than 0.040" clearance over the pistons and hand to do some grinding. See here:
https://www.fordbarn.com/forum/showthread.php?t=302368
The ignition system is part of my home-built EFI system using Megasquirt. It uses a trigger wheel which I brazed to the crank pulley and an EDIS ignition module from a 90s V8 Ford. The coil packs are GM which have the advantage of using a more standard ignition wire boot. I put a bunch of miles on everything this summer and am really happy with it!
A772FC73-578C-4782-9812-EC4AD0352756 by
kenhenry_06268, on Flickr