Need Help with a Crank but No Fire issue

LOL well no, you don't. You need a 4 pin ballast if you have a 5 pin box, but a 4 pin ballast will work with either a 4 or 5 pin ECU

You need to take a measurement and figure out WTF is going on, and don't disregard loose/ corroded/ intermittent connections.

With key "in run" engine stopped, coil + should see something around 6-10V If you have a pin probe or even a sewing needle/ pin, backprobe the power terminal on the ECU and make sure it's getting power

Then with key "in start" coil + should see "same as battery" IE if battery is 11.2, then coil should be same. In no case should coil+ be below 10.5V