This is how I built my pc oscilloscope https://m.facebook.com/profile.php?id=1550130231927891&ref=content_filter

No just if you dwell them for to long they will cut the 5v signal themselves and fire a spark no matter the crank postion it's a nasty kick back when they fire on the compression stroke well before...

The truck coils with finned heatsinks self trigger with too much dwell to stop them overheating it's the built in protection.the delco ecu I use with an external ls1 coil driver box the cranking...