The only way to fly with plug wires, new or old, is to test the resistance, and compare to spec.
My new Delco wires all tested at 8,000-9,000, which is ridiculous, and my Wagon runs so much better since I tossed those, and replaced them with stainless steel marine wires, which tested at between 900-1100.
Never checked MSD wires, but Taylor wires generally ohm to around 240-300, and Granatelli wires at less than 100. If they weren't always on a 6 week backorder, I'd have those already. Oh well, one day soon.
Good call on the NGK's. The Delco plugs are not what they used to be, and my engine runs alot better with both Delco products gone from my engine bay.