sparkplugs and wires

For a 460 or a 454 engine of that vintage I would get the Taylor 10.4 mm wires they are made to withstand high heat produced by both of those engines. They come with a FG sox that fits over each spark plug. If you start your engine at night and look closely at the wires you are likely to see small arcs for the wires to the engine block(ground). These thinner wires(8mm or less) will break down after a while from the high heat. I would just get any of the majors brands of spark plugs. Are you showing any codes yet from the backfires?