Why won't my truck start?

I have tried this but for assurance I just did again. It will not start by doing this.

Pull coil wire from distributor cap... Test spark to see if it will jump a 3/4 " gap... Put coil wire back then test a plug wire to see if spark is the exact same.. You'll need a helper.

I have tried this as well. Spark is good. I changed the water pump 2 days ago. Started and let run to check for leaks. I let it run long enough for thermostat to open. All was good. I put it in reverse and it died. It hasnt started since. I'm not sure if any of that info helps.

Well let's see here: It's got good hot spark and we know it's got 'fuel' from carb cleaner.. No timing chain problems at all on that engine...I'm out of ammo!