fuel or ignition problem?!?!

[78burban]

I just put a new cam in my 350 for my 81 c-10 it has a
brand new carburator and all new components for the
distributor (control module, rotor button,coil and
cap) including wires and spark plugs. now the problem im having is when i installed the cam started it up ran excellent let it run 20 mins varying the engine rpms to break the new cam in. i
drove it about 10 times down the street and back and
playing with the timing so i fianlly found the best
timing 8 btdc was running damn strong then all the
sudden it shifted into 2nd and just stalled out. got
it back to my house looked i couldnt find anything
wrong. started it back up had a hard time starting and
when i finally got it started back up it would start
then die after 5 seconds sometimes it will sound like its running on 3 cylinders if i give it any gas it will stall out. what do you think this could be. the truck has a brand new rochester rebuld
carburator on it. Please help me out