I purchased this kit to match a car I purchased with gauges and a ignition panel already installed and it made it as simple as can be. Not a bad price for the peace of mind.
50-2032 Ignition Harness HEI Weatherpack
Universal weatherpack wiring harness is designed for applications using a HEI ignition system. Harness is constructed using weatherpack connectors , heat shrink tubing, all soldered connections, and includes connectors for hooking to an HEI distributor.