Help!!

[Jbaca13]

My name is Jonah I am new to this forum, and I am trying to troubleshoot a problem me and my pop have been having with our truck for quite sometime. We have a 1970 C10 Pickup, 350, has a set of headers, flow masters, and not too long ago we put in a 700R4 on the floor. I mainly drive this truck 95% of the time, as my pops will drive it the other 5% of time. This truck has been a dream since I was little to be able to drive it all the time, I drove it during high school minus the time taken during fixes or time in the shop. This truck means a lot to me and it's a way of anti depressant for me, nothing soothes me more then going for a cruise in my truck. I'm in college now and I was unable to bring my truck with me, but I want to go home and bring it back up to college without worrying if I can make it back.

The truck will bog at low RPM's, for instance at a stop sign and then getting off the brake and getting on to the gas it'll struggle till I build up to about 30mph. Or cruising around 35mph and doing a pull the truck will lag for a couple seconds and then kick. That's one problem.
Second is that when I would drive it for a period of time (running errands around town) the truck would just shut off. I would have to kill the ignition all the way, then turn the key and she would start right back up. Now this at times was really dangerous for me, and I would not want that to happen on the highway.
We have tried to deal with vapor locking in different ways, such as putting a high-rise intake manifold for more airflow, and putting on a electric fan that is manually controlled in the cab. We have had the distributor tweaked with. The carb is fairly new. So personally I don't know if it's the wiring, or something with the fuel system. The carb is not starving for gas at all.
I hope someone can give me some ideas or tips on what to try so we can solve these couple of issues.