[BigAls87Z28]

I removed the carb the other day to tighten down some of the intake bolts that seem to have come loose on the 72. I damaged the carb gasket, so I picked one up at the PT job.
I tighten the intake bolts, put ont he carb, hook it back up, and now it wont stay on.
I turn the key, fires up, then dies right off.
Im thinking this is a fuel issue since most if not all the fuel in the bowls are gone, but I would figure that its been filled since, no?
Once I get it going, if I press on the pedal, it runs like ****, hoppin around, almost like the timing is off?
I made no other changes other then removing the carb, and putting it back on. Any ideas?