1974 k10 Chevy 350 motor w/ Carter carb, when driving down the road when warm it cuts out and sputters. If I put it into neutral and coast (with the engine idling), then back to drive it will run a few seconds just fine. If I turn it off and sit for a while, it will run fine for a while till it gets warm. It does this in the summer or the winter.

I have replaced the fuel pump, fuel line to the carb, all hoses into/out of carb, Distributor cap, ignition coil, spark plugs and wires. My grandpa bought this truck new, and I am trying to keep it going!!

 

just a thought, but possibly the head gasket(s) are gone. so when the engine warms up and the thermostat cracks open, the water goes into the cylinders. i had a similar problem with my 81 parisienne. give that a shot. you should be able to check that out just by checking the plugs, possibly. or, just keep an eye on the water levels...or, the best way is to see if you exhause smells sweet.

give that a try.