Modern HEI, standard points,...
Modern HEI, standard points, or vintage dual-point--no matter what your particular flavor of ignition may be, it needs to be in proper working order (i.e. good condition) to work properly!
More often than not, it's the simple things that end up causing the most trouble. Take, for instance, spark plugs and wires. The tiniest break in your engine's ignition spark anywhere between the distributor and the plug can wreak all kinds of havoc, and you may not even be aware of it. Be it damage from heat, wearing over time, improper installation, or simply a dislodged component, if your plugs and wires aren't in tiptop shape, how do you expect your engine to run at its best? Whether you're running a modern HEI (High Energy Ignition) or a basic points-style ignition, each individual component is only as strong as its weakest link (gee, where have we heard that before?). keeping your ignition system healthy is "key" to ensuring your engine's well-being down the road...literally.
But not all ignition systems are created alike; furthermore, not all ignition system components are created to function properly with one another, specifically on what's referred to as the secondary side of the system-namely, the wires. While perfectly suited for race applications, where interference such as radio noise isn't a concern, solid core wires can actually do more harm that good if used with an HEI or electronic ignition; thus should only be used with points distributors or magnetos for the most part. For all electronics, stick with a good insulated wire. If you want the nostalgic look, run a nostalgic system, be that a magneto or an old Bakelite-cap dual-point unit. In that case, you can also throw on a set of transparent Standards from Mooneyes or even some good old N.O.S. cloth-wrapped wire with some Raja-style tips!
Along with not only identifying, but also using the correct wires for your ignition, you need to maintain your system, as well. That means knowing how to make your own wires if necessary. Despite the fact that many wire sets come pre-cut, if the time comes that you need to replace a single wire, or worse, build your own from a universal set (heaven forbid), wouldn't it be nice to be able to do so on a moment's notice? And crimping ends doesn't require a bunch of expensive tooling (though there are nice crimpers available) as you can obtain simple vise-attachment type devices for cheap, but many cut-to- fit plug wire sets come with crimpers included. If you're already inclined to this sort of thing, then you should already know the difference between HEI and standard or socket-type wire ends (general Motors' HEI distributor ends are the same as the spark plug ends, in case you weren't aware), but the actual crimp "style" is just as important to know, as that can literally make or break a solid connection.
Finally, when it comes to the final destination of your ignition's secondary side-the spark plug-condition, type, and even setting all play important roles in performance. We all know how a fouled plug can, well...foul up an otherwise good-running engine, but at the same time, improper gapping and even incorrect type can also be contributing factors (though it's not as common to find the "wrong" plug being used). And it's easy to determine if your plugs are to blame-even easier to correct. For most points applications, tighter or smaller gaps (in the .025- to .030-inch range) are common; HEI and newer fuel-injected applications will call for wider gap settings in upwards of .060-inch. Now, getting the settings may not be difficult once you're familiar with what works and what doesn't, but choosing the right plug to begin with might very well be, as there are so many options available these days: iridium, multi-electrode, platinum, and so on. For all intents and purposes, the fancier ones may produce more spark; some, on the other hand, just look fancy. unless you're up for a bit of trial and error, which can translate into trials in upwards of $25 per plug (and up!), stick with the basics we've all come to know and love over the years.
 Let's start with your ignition's...  Let's start with your ignition's main arteries: the plug wires. Pictured are two examples of commonly used wires stripped down to their cores to reveal the difference between solid (R) and spiral-wound (L). The added insulation on the spiral or carbon-core style wires provides the necessary suppression to reduce radio noise (EMI), but can also reduce the amount of voltage a wire can carry, which is why the aftermarket offers improved components. |  Solid-core wires are just...  Solid-core wires are just what the name implies--solid copper-strand cores, much like typical electrical wire with the exception of a much thicker housing to help keep the spark from jumping, and ultimately grounding. While standard crimp ends are normally used, solid-cores can also be equipped with the old-fashioned Raja-style ends--keep in mind, though, these up the chances of errant spark behavior if used without shielded housings. |  Shown are an HEI female-style...  Shown are an HEI female-style crimp end (top) and a standard socket or male-style end (below). Note that the HEI tips are used for both distributor cap and plug terminals in HEI applications; just the plug ends in points applications (they provide a better "grip" on plugs than the older versions). |