Does anyone know a source for a 1974 big block positive battery to starter cable harness?

I had the car out today and after a stop it didn't want to start again but it finally did and I got it home where it did the same thing after shutting it off. This time after some attempts at starting I got smoke and discovered the battery cable on the header. Now it won't turn over at all and the cable is pretty crispy so I'm presuming this is my issue. By the way, if this was in the process of burning up going down the road would that cause my tach to jump around? I'm hoping so or I may have another issue also.

Thanks,
Dave