Engine Died on 1st Ride Won't start

I'm almost done with my first restoration. I put a 72 340 into a 68 Dart. I broke in the engine about a month ago. I've been starting it and running it till it gets nice on hot every 2 or 3 days. I took it for a ride for the first time last night. I went a mile down the road and back. When I got back, the car stalled right in front of my garage. The starter cranks but the engine never tries to fire up. It is getting fuel. I pulled a plug to test for spark. My wife cranked the starter a few times. I only saw one spark and it seamed weak. I had my choke hooked up to my coil causing the terminal to glow. I've since hooked it up to the input side of the ballast. The engine always started as soon as it cranked. I have a multimeter (used it once to find the input side of the resistor). I'm going to put a new coil and resistor on it tonight. What kind of diagnostic tests should I do?