With a broken chain the engine won't run at all.
The only fix for broken timing belt or chain is to replace it.
A Dodge Durango does not have a timing belt. It has timing chain. If the timing cover chain gasket is leaking it is normal to change it while changing the water pump.
A timing chain, that needs to be replaced, can cause your engine to run rough and lose power. A broken timing chain can cause significant engine damage.
The engine will not fire. Remove the distributor cap and turn the engine over. If the rotor does not turn that is a good sign the chain has broken.
there is no timing belt on a 318cu it has gears and a chain for timimg
The roll pin in the distributor drive gear may be broken. Remove distributor and check. Camshaft broken, But not very common in stock engines. Timing chain broken. Not common either. Cam gear on the timing gear may be striped off/teeth gone. Check timing chain.
Under the timing chain, on the front of the crankshaft.