Greetings all. While I realize a DUI is only slightly better than a DWI, it's a lot better than a stock points dizzy. I've been looking for a new one and a little advice might be useful. The choice is between an HEI and the DUI. Classic inlines boasts some serious performance with the DUI, however, it doesn't really stand out over the HEI from CRT Performance. The only visible difference is about $200 and change. I have a 200 inline so I don't need a high rpm dizzy. Thoughts?
The HEI types don't allow much clearances. With the coil being on top, the caps are a lot larger in diameter.
Build a HEI Box I converted my DUI box to house an HEI module. It's real easy! I put the DUI into the oven at around 300 degrees. (Bake until golden brown - lol) It smells up the kitchen, though. Take outside, and using a knife, screwdriver, putty knife, etc. the "guts" come right out. Clean it up, make an aluminum "pad" for the HEI to mount on; and it wires right up (using lugs). Yes, the DUI is electrically a better circuit - but, considering cost and ease of replacement - I think that the HEI is a better deal. (I work in electrical engineering for Garmin).
I have HEI on mine, 5.0, and it spins fine to 6500 rpms. I was afraid I would lose some power up top, and maybe lose some rpms, but it feels as strong, if not stronger, than it did with the old pertronix-in-stock-distributor setup with MSD 6A. No longer using the MSD box, either. But it is a BIG thing under the hood. Had to lose my round air cleaner and move some other things around to fit it in there.
Keep the small diameter, stock appearing distributor and out a Pertronix in it. HEI belong on Bowties, period. Hate the look of that big lump sitting on a Ford engine. SPark
Here is a good read on why I don't like HEI style distributors. http://www.ifsja.org/forums/vb/showthread.php?t=19440 I know they are talking AMC and not Ford...but AMC used a Ford distributor. Here is another link also. http://www.junkyardgenius.com/ignition/jeep/HEIcompair.html
The coil packs are always going to inherently be too small by design. And they are fugly too! Any mag pickup style disty(Duraspark is a good tough design) with an external coil will beat those modular "all in one" units by a country mile. Unless of course.. "good enough".. is good enough. It's not like many ever care how their engine looks anyways. haha.. I kid.
personally ive used DUI for years on my impala, the whole idea of dui, is to have your advance curves set. they do all the calc's and modification for you. ive had alot of luck with there products. they are expensive. they are located here in memphis so i can just drive to there store and pick stuff up.
HEI sucks.. especially the ones Summit sells. I had one in my '72 C10 that had a '89 5.0 H.O. motor out of a Mustang in it. It worked fine for the first year or so, then it started chewing the upper shaft bushings. I replaced the upper bushing 4 times in less than 3,000 miles before literally throwing the distributor in the trash. When the bushing wore down it would allow the reluctor wheel to drop down on the pickup coil and would start chewing that up until it just randomly lost fire and left you stranded with no warning... On the other hand, the Duraspark II/MSD6 combo in my Maverick has been in the car through three engines and over 200k miles and has NEVER given me a single problem. Hell, the MSD plug wires on the car right now have over 100k on them...
Hmmm. I am using the Summit HEI right now. Fairly new, and no problems yet. Hopefully they rectified the problem since you bought yours. So far, I am happy with it. Less wires, spins fine to 6500 rpms. everything I need, currently (pun intended).
