Suddenly Running badly

[Minkota]

It is a 350 small block V8 with a 350 transmission, MSD Ignition, New Spark Plugs, Cap, Rotor & Wires. Carb is a Carter AFB Competition Series 9605S

I was driving the truck and it was running perfectly and then out of nowhere it stuttered and died (no, it is not out of fuel). it fired right back up and runs fine (idles at around 800 RPM) but then when I put it in gear it will drop below 500 RPM and stall. when I first start it (cold) it will go into gear and drive but does seem to act a little strange but after maybe a quarter of a mile it will begin to stall when I come to a stop if I do not put it into neutral first (it does NOT have to be up to temp before this happens).

I sprayed some starting fluid around and found a small vacuum leak at the base of the Carb so I replaced the Base Gaskets and fixed the leak. I have not found any other vacuum leaks. I blocked the Brake Booster Line and the PVC Line to eliminate those as a possible vacuum leak and neither had any effect.

My next thing was going to be to rebuild the Carb but I am not 100% convinced this is the issue as it was running great and then suddenly it wasnt. I can find no other vacuum leaks I thought maybe it wiped a Cam but I do not hear a loose rocker and it does seem to run fine when not in gear so I am fairly certain it is not a bad Cam.

Any suggestion would be greatly appreciated....