I did the Ignitor II on my previous 400 build. This time around on my 455 build, I bought a complete distributor, Ignitor II.
I didn't have any problems out of it in the 25,000 miles I got out of the 400. I did not install the kit while the distributor was in the car as I was rebuilding the 400 engine at the time. I actually purchased a (cheap) rebuilt point style distributor so I know it was tight and had a new gear on it, and then installed the kit.
If it were me, and you know and/or are comfortable doing this, I would set your distributor on No.1 cylinder just as it would be firing along with the correct timing mark on your crank pulley, and pull the distributor to work on it. You could also inspect the distributor as well. With small parts and my big hands, I already know what would happen as I were leaning over the fender trying to install the small screws in the points plate -and then I would have more work on my hands, and probably have to pull the distributor anyway. Once finished with the conversion, just set the distributor back in -which can take a couple tries to get the rotor in the correct No 1 position.
This time around, I matched the distributor with the PerTronix Flame Thrower II coil and got some Taylor 8.2 mm wires off of the Summit site. Not installed or running yet, but that is what I got.
Spark plug, You don't need anything "fancy" or "gimmicky." Just plane old AC-Delco or Champions as recommended for your engine. You could probably open the gap up to .40"-.45" as opposed to the factory .035". Personally, I like a little tighter than wider on the gap, so .40" is what I use.
From a HotRod magazine online article:
"Controlling the operating temperature of the plug’s firing tip is the single most important factor in spark plug design. “Heat range” is the relative temperature of the spark plug’s core nose, and it is determined by the length and diameter of the insulator tip, as well as the ability of the plug to transfer heat into the cooling system. A “cold” plug transfers heat rapidly from its firing end into the cooling system and is used to avoid core nose heat saturation where combustion-chamber or cylinder-head temperatures are relatively high. A “hot” plug has a slower heat transfer rate and is used to avoid fouling under relatively low chamber or head temperatures. What’s confusing is that a “hotter” (higher performance level) engine requires a colder plug because more power equals higher cylinder temperatures.
, then they throw this out which almost counters the above heat range guide: Gasoline quality: With musclecar-era leaded gas, the lead is attracted to the hotter (core-nose) part of the plug, causing glazing. The spark runs down the core nose instead of jumping the gap. Going to a slightly colder plug helps prevent lead-glazing. However, with today’s cleaner-burning oxygenated unleaded gas, an equivalent engine needs to run plugs about 1-2 heat ranges hotter than originally specified (many plug manufacturers have revised their catalogs accordingly).
With a new or unknown combination, play it safe. Always start at least 1-2 heat ranges on the cold size of the mean heat-range for the series of plug you are running. At worst, you may experience some plug fouling. On the other hand, a plug that’s too hot can cause detonation and damage the engine.
Read more: Spark Plugs Fact and Fiction- Car Craft Magazine
So, on spark plugs, you may actually want to experiment a little by selecting the stock heat range for your engine and then go 1-2 steps down or up to possibly zero in on the best range for your particular engine combo.