Bought a new car this morning

Picked up a beautiful 1964 Valiant. Slant six, push button auto, 2 door. Under the hood , the 225 has a Clifford intake, 4 barrel carb, Clifford split headers with true dual exhaust. Long story short I drove it about 250 miles before I had problems. After a lunch stop it would not start. Getting fuel, getting spark, car just cranks. I fiddled with it a bit and kept trying
It started again so I drove it another 100 miles. Until I stopped for fuel. It started up immediately but on leaving the gas station it stalled on the street and would not start, just crank. I called a hook to take it the rest of the way home. Right before the guy hooked the car the car started again for a moment, then stalled again. Anybody have any idea what is going on here. This car is costing me 500 bucks to be towed to my house. Thanks in advance for any help.
Chas