HELP! 66 won't start

So my 66 with a 302 has been dead in the water for a few months now. It was running OK when I took off the intake manifold and distributer to clean and powder coat. While everything was apart I put in new plugs, rotor, cap, and wires. Now it cranks but won't start. Put first cylinder at TDC, found timing mark on balancer and stabbed the dizzy. Might be 180 off but I made sure my finger was being pushed out of the cylinder verifying the compression stroke. I have spark at the coil, verified that by grounding it to the intake manifold and cranking it. It was a white spark though (should it be blue?). I have a new coil I'm going to try tomorrow. Got a loud backfire once.

I set the firing order to 15426378. Not entirely sure what year 302 but I'm sure it's an older model because the oil dipstick goes through the timing cover. It's on my to do list to check the block #'s to verify what year it is.

Previous owner converted it from points to petronix ignition. Also threw a new Edelbrock 9906 carb on it. But it still wouldn't fire with the old carter AFB carb on it.

Tomorrow I plan on testing spark on each wire and putting in the new coil. Anything else?

Please help guys, I'm pretty new to classic mustangs and carbs. I'm a fox guy that got lucky and found a good looking '66. I may be missing a few details that have escaped me at the moment. Let me know and I'll fill in the blanks. Thanks!

I messed around with it today and set the timing again. I think it was 180 degrees out. Also put in new coil. But didn't even get a chance to start due to a dead battery. Stupid red top wont even hold a charge anymore. Gonna get a new battery this week. Thanks for the help guys.

Still dead. Won't backfire. Turns over fine but won't start WTF.

Had a mechanic friend come over an help me out today. Found out the timing chain was almost 180 degrees out of whack. Previous owner must have somehow timed it so it would run. This explains why the engine never ran well when it did actually run.

Spent the rest of the afternoon tearing off all the accessories and water pump. I will be upgrading to a double timing chain.