Re: Plug/ignition wires for 56 Packard 374 v8

Posted by BH On 2009/12/13 11:44:21

Bowman -

Just to clarify, all Packard V8s had some sort of spark plug wire support brackets. However, the '55s and early '56s only came from the factory with what they called the finger type supports. Those later supports could be installed on earlier cars from either year, but some never got them - perhaps never demonstrated the need. Personally, I prefer the redesigned supports.

Go to the "Electrical" section of Steele Rubber's online listings for 1956 Packard and look for their item #70-2052-21, which replaces Packard #439833. (Strange that they haven't also repro'd the support bracket grommets.) Though the illustration doesn't show the 135-degree (some refer to it as 45-degree) angle, take note of the ribbed detail. If your spark plug boots look like that, they are likely to be at least authentic service replacment wires, if not the original factory install.

Due to heat from the engine in that area, the spark plug boots were typically the first part of the OE wire assembly that failed, but the wire itself held up very well. I've seen engines on these cars where there ws nothing left of the boots, but they still still ran well. However, the lack of a boot does pose an electrical hazard in close proximity, with the engine running.

My OE wires had a metallic core with a bright finish, which I assumed to be steel, perhaps stainless. I never looked into it any further or checked to see if the core might have been tin-plated copper, but it was comparatively tough material to cut. I've also heard these wires commonly referred to as steel-cored in casual conversation.

Suppresion type wires usually have some sort of non-metallic core that's impregnated with some form of carbon, which serves as a conductor but also as a suppressor. Wires with that type of core and silicone rubber insulation are quite flimsy and require additional support (as found on more modern engines).

Let us know how things pan out.