okay! so i can get the new engine wiring harness and new dash harness to convert from idiot lights to guages - 70 Malibu. Will the existing headlight harness connect into the new engine harness or do i need to get a new headlight harness too! I'm left handed so this electrical stuff is a challenge. bruce

Everyone is born right handed. Only a few improve.
You will need leads for the ammeter added to the engine harness for the swap. May consider having the ammeter convertered to a true voltmeter. A little safer.
*Edit*
Ammeter leads go into the forward lamp harness not the engine harness.