First review this thread:
http://www.forums.IHPartsAmerica.com/ignition-tech/644-ignition-system-performance-upgrades.html
My personal opinion...the delco hei ignition is a very poor choice for any engine. It's nothing more than an inductive system that incorporates a magnetic trigger. It was barely state-of-the-art when intro'd around '72, and was surpassed tech-wise soon thereafter by many other manufacturers.
Yes...I know we market those units...but they are very problematic when attempting an install due to their physical size, and the drive system is total custom which means in the case of the IH-converted unit must be done correctly in order to prevent cam drive gear damage.
For a "conventional" ignition system that is simple to set up for the normal enthusiast and is state-of-the-art still after 30+ years, a pertronix conversion, used in a delco distributor, and wired through a msd/mallory/crane "six series" cd box can't be beat, especially when used with a companion, matching low primary resistance ignition coil. And run that connected to plugs gapped at no more than 0.045".
I prefer the delco distributors due to the ease of dialing 'em for the advance curve if desired, and their durability. And if a vacuum advance system is retained, for relatively few bucks, an adjustable vacuum advance can is available for those. That allows total custom tuning for any engine application of level of performance parts.
The pertonix unit May be used either stand alone (the so-called matching performance coil is a total waste in my book) with an oem coil or be used to trigger the add-on cd box, so this significant upgrade May be done in stages as budget allows.
The three different "six series" cd boxes are all virtually identical in actual operation and design (even wiring). One has no advantage over the other except for appearance and bells/whistles. No freakin' way any IH motor needs a "rev limiter"! But they need to be the "analog" versions, the p-tron won't work with the "digital six" msd.
The inductive dui distributor doesn't come close to the max kv potential available using the aftermarket capacitive discharge system combined with a properly matched secondary coil.
