The vehicle is a 79' Dodge B300 Extended Cargo Van. Powered by a LA360 5.9 V8 2bbl 2210/2245 Holley carb. Tranny is 727 freshly rebuilt.

So I recently rebuilt the tranny on this thing and drove it for the first time in about a year and it drove great for about 20 miles and then CLACK! the driveshaft was dragging... When I installed the driveshaft I didn't put the clips in the caps that get clamped. That was completely my fault and was able to get that fixed.
So I got the driveshaft hooked back up and thought I was good to go...

I cranked it and it wasn't starting, it finally started but was running rough and died after about 5 seconds... I cranked it again and it started backfiring out of the carb. It wouldn't start again and I ended up killing the battery which apparently was no good anyway...
I noticed the carb was leaking all around the gaskets so I took it off and tightened everything I could and it still leaks. It won't start at all now! I've removed the carb for a rebuild and ordered a Carter rebuild kit.
Could this be a carb issue? It's obvious the carb needs a rebuild either way...
I checked the spark and the ignition seems good...

What the heck is going on with this thing??? Please help!