I have a 1954 half ton with a 235 that has dual Rochesters through a Fenton dual intake manifold. When I'm travelling at any speed over 45 mph, the engine starts missing as if it's not getting enough gas or intermittant spark. When this happens, the engine will quit and after sitting for a minute, I can start it and drive it just fine; so long as I don't go over 45 mph. There's no vacuum leaks and the fuel pump seems to be working alright. I had a Pertronix ignition system and changed it back to the points to see if that was the problem. The problem still persists. Any ideas as to what the problem could be?
