Engine Mechanical problem
1978 Other Plymouth Models V8 Four Wheel Drive Manual
I have a '78 trailduster with a 360 engine and a wber/carter competition carb. Truck started out losing power when shifted into 4th gear. Having to down shift when going up even a small incline. I turned enginge off and will not start again. I almost stars the first try and after that engine just cranks until battery dies.
When diagnosing a no start situation you should check the three basic conditions that an engine needs to start. These are engine compression, fuel, and spark. By your description I would start with checking for loss of spark and if the fuel is available from the carburetor.