Difference in ohm rating on plug wires?

Years ago we were told that the "upper limit" was 1K/ft. I've never found one that high, unless it was open.

Modern wires are a completely different ball game. Some are magnetically suppressed, and 'I guess' some of that type are not suitable for EFI applications

There are a few stories around the 'net where plug wires caused MSD and other ignitions to self/ false trigger, and in once case drove the VR nuts