1970 Dart Swinger V8 Restoration

The gas tank was seeping gas through a rust hole, so I pulled it out of the car this weekend. I was told the reason why this engine wouldn't fire was the carburetor, so I rebuilt it and discovered the wrong metering block gasket was in there. Replaced the gaskets and tried to start her, but no luck. The engine would fire and then immediately die every time. Eventually I realized it was dying when the key was released into the ON position. So I tested all the pins coming out of the firewall to find their voltages at the different key positions. The electronic ignition box was getting 12v when key was in Start, but little or no voltage in ON. Turns out only one pin is wired for 12v in both Start and ON, so I jumped the wire into another 2 coming off that pin. After that it started right up! Right now the car is basically sitting awaiting a new gas tank, which I have yet to order. I've seen tanks for 115.00 and free shipping on eBay but am hesitant to immediately go for the cheapest option, poor though I may be. Hope to get back to work this weekend, sort out the timing, replace the turn signal wiring harness, and sort out more wiring issues.

A couple quick questions maybe somebody could give me a hand with. As for timing, right now its set at 0 degrees TDC, any recommendations for what it should be set to? Doesn't your camshaft have a big effect on your timing? Unfortunately I have no idea of the specs other than it's 'mild'. Also could anyone identify the electronic ignition box or tell me more about it, like if it has a rev limiter? Can anyone identify the rear end at a glance? Sorry for crappy angle.