Engine dies, but turn the key off and back on it fires right back up
It just started in the last day, to die driving down the road.
Intermittent like that is always trickier to solve.
I agree check for loose or oxidized connection is good idea.
Glance at the ammeter next time this happens. If it shows a slight discharge then the ignition is still drawing some current. If not, then the ECU or distributor pickup or connections are suspect. Its a small draw so will not move the needle much. You'll have to be the judge on that.
Coils will sometimes die intermittantly, but I;m leaning against that since you can restart immediately. Do check the connections though.
Since the ECU wiring is add on, check the new and old connections.
If it tends to die at higher speeds or under slight load, and worse in warm temperatures, could be winter fuel causing vapor lock. It will die similar to running out of fuel (which it is) but letting off the gas pedal is often enough for it to stay running.
Second question is it worth the extra couple hundred bucks to go to a MSD box
No. Capacitive discharge system has some advantages with higher compression and higher rpm applications. Otherwise, on pump fuel, a kettering system is just as good and arguably better.
just buy a summit brand orange ecu
I'd prob just try to get one that's been tested good, a standard LX101, or 'High rev 7500' in that order.