Silverback Carbs

I was gonna get EFI on my 496 build to keep the height down and fit my cowl hood. A very knowledgeable Mopar guy near here is also a Holley EFI tech rep. He said he wouldn't do my Demon unless I let him rewire the entire car as the 44 yr old wiring was spurious and would not provide a good voltage / ground. Staying with the carb.