Hello, I have a 1963 valiant with a 1978 super 6 engine. It runs perfect around town and for short highway drives. But if I go for more than a hour straight it won’t idle at all. If I let it sit for roughly a hour to cool down it will run perfect again. Still will run fine at speed. It’s not choke, it’s not carb, I’ve checked and adjusted timing and all the advances. Does it need one of the fuel filters with a third nipple? I think they filter the gas vapors from the gasoline. Any input...
Slant 6 hot running issues
