I have a 77 bronco with a c-4. The previous owner must have been a moon shiner. He made the coolant lines out of copper. Is there a rubber lines available that could be used or is steel the only way. The wiring harness is shot on this unit as well. How big a job is it to replace the old harness. I see you have this harness listed as 66-77. How is this considering mine is electronic ignition? thanks