Duraspark vs. Pertronix


Well-known member
I have a '70 cid 200 in my 66 coupe. It has a dual vacuum distributor in very good condition. I an going to upgrade the ignition. In your opinion, is there any significant difference between the duraspark II and Pertronix as far as performance? It would seem easier to add the Pertronix and their coil since my distributor is already good. Also, is the new Pertronix Ignitor II system improved enough over the original to justify the extra money? Thanks.
Hi Russ,

You have asked a question that could set off quite a debate, DuraSpark vs. Pertronix. I favor the Pertronix II because the technology is newer, the performance is excellent, and reliability is better (I'm it trouble now).

Reliability. While this comment is second hand, I will say that I have not met a Ford machanic who hasn't said that the DSII "box" is unreliable. As a matter of fact, I had one tell me they made it a policy ..."back then"... to keep several on hand because they had to switch them out so often. As for Pertronix, they DO NOT perform well without a 12 volt hook-up. So, there a are lot of Ford owners out there who did not have a good experience with the Pertronix system. Why? Based on a response to an MCA letter, which response was published by MCA on their sight, Pertronix determined that there installation instructions were not clear. As a result, many of the users reporting poor performance had powered the unit via direct hook up to the distriubtor, which is NOT a 12 volt switched source. This problem was solved with the Pertronix II.

Technology. The Pertronix and the DSII are more than 20 years old. In the case of the DSII, it has not been used since the advent of fuel injection (mid 80's). The original Pertronix unit is more than 25 years old. This not to say that they don't work, or that you will not have good luck with them.

Pertronix II with Flamethrower 2. About two years old. Upgrade 1 - converts coil to 12 volt by eliminating the ballast resistor in the coil circuit (this is a good thing). Upgrade 2 - the system has built in dwell control. This helps to insure maximum spark signal throughout the RPM range (one would have to add MSD to the DSII, at a cost of $150+, to get this function). Upgrade 3 - the system has a built in circuit protector to prevent burning up the module if the key is left on while the engine is not running, i.e., if you set and listen to your sound system. Bottom line, for $115 you get a 12 volt system with a 45,000 volt spark and dwell control. As a side benefit, this unit can be installed in about 20 minutes (easier than replacing points).

As a final note, the fact that you want to upgrage your dual vac distributor begs another question / comment. What are your long range plans for the car? Specifically, do you plan to add a performance carburetor? This is an important consideration because (and I learned this lesson the hard way), NONE of the typical / popular performance carbs (Holley or Weber) support the dual vac dizzy, and the Pertronix unit that fits the dual vac probably will not fit the single vac dizzy required with these carbs. So, if you invision a carb change somewhere down the road you may want to upgrade the the dizzy when you do the Pertronix II. This way you'll be ready for any carb change you may want to make, including one that would require a mechanical only set up as the single vac unit is easily converted. In this regard, when you purchase your rebuilt single vac dizzy (about $65 with new cap and rotor) be sure to order / purchase one with the 10* weight set-up.

Hope this is helpful.

hey there. im in the same spot as you. i havent tried either of the setups yet but i have put on a rockin msd blaster 2 coil! it worked wonders. throttle responce was excellent and it starts even better than before. of cource my preveouse coil was rusted on the inside. :cry: if you want my opinion i would go with pertronix 2 as well. but if your short on cash i would go to a parts store and get that msd blaster2 coil. its only like 30$ and its a great improvement!

First On Race Day
I am a little paranoid. I drove my stang to Massachussetts and back in 2000, and Dallas-DC and back in 2002. I don't go anywhere without my toolbox, with enough tools to do a minor overhaul. ;) One thing I like about Pertronix is that I carry the points in the trunk. In case of an electronics failure, I can slap the points back in and be on my merry way in a few minutes. :D
When I first installed a Pertronix in the original engine in my Mustang in 1995 I put a spare set of points in the glovebox. I haven't touched a set of points since.
Interesting... I have just finished converting my '83 Ranger to the DSII setup. If you go to http://therangerstation.com forum, that is a very common modification for the 2.8L V6 for reliability. Of course, the stock setup is the computerized carb, which is a real POS. When I did the swap, I also switched to a '74 Mustang II intake manifold with a homemade spacer so I could tap into it for manifold vacuum for the brake booster. I put a Holley/Weber 5200 on and now it is as reliable as sand in the desert. I've just bought a ('70?) Maverick with 62000 miles on it, so I'm interested in swapping out the points (I assume it has points--- It has the small diameter distributor.) for an electronic setup. I've always heard the DSII was very reliable, but some do use the Pertronix setup--- I always thought it was the off roaders who wanted to carry points as backup. by the way, the Ranger still passes emissions, probably helped by the fact that the H/W 5200 is a little small for what the little V6 can flow--- lots of guys put a Holley 350 on for performance, after swapping in the DSII. The other thing to remember is tha the DSII box can be had for $10-15, if you're really into carrying spares.