My Chevelle died on me today.....

[Chevelle_Nut]

It sounds like to me your carb needs a good overhaul. The Rochester 2bbl is easy to do but the throttle plates have a habit of wearing and need to be rebushed. I would start with the carb since it is flooding.

You need to fix that exhaust leak, carbon monoxide is dangerous. Doughnut gaskets are cheap just use plenty of PB Blaster on the nuts first.

Lets get the thing running safely before getting on the fuel gauge, more than likely you will have to drop the tank to fix it.