C10 won't idle

[Scott_williams2]

So I have a 68 c10 with a 250 I6. It ran fine for 125 miles then it started buckin and stealing doin down the road. So I cleaned all the lines, replaced the fuel pump, cleaned the carb, and cleaned out the tank. It ran like a sewing machine the rest of the day. I woke up the next day and it hard started which had never happened. Then it wouldn't idle unless I gave it gas. I drove it another 25-30 miles until it go to where it would die without gas and it was missing terribly and really hard starting. So I replaced the gas tank and just got a new carb, new plug wires, new plugs, new dist cap, new rotor, new coil, new points, set the gap to .19 and set the timing to 8 degrees BTDC. I replaced the carb yesterday and adjusted it to where it now idles for 30 seconds but the rpm rises really high randomly and it dies. I'm stumped. Any help would be appreciated