Anyone tried a DUI (Davis Unified Ignition)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

never used one but I suspect that it is just a a mdofied HEI style distributor for bolt on application

cuz normally to put an HEI you gotta switch the gear in the distributor to the landcruiser one

its probably pretty sweet :D
i've put one on my fj40 and it runs so much stronger. i would recommend it to anyone who wants a smoother running engine, better throttle response, slightly better milage, better torque in the low end, and cut their idle in half!
besides power steering this is probably the best upgrade i've done for runnability.

hope this helped you.
But is it worth $375?
You could get a HEI for a lot less and change out the cam gear. I'll need a new dist. to put on my F rebuild soon.
There was a tech article in Four Wheeler or Petersen's 4 Wheel about a year ago about installing this distributor in a 78 40, they had a lot of positive things to say. :D :G
Or you could spend less than $100 for a used HEI from a junkyard, and some custom wires. You could spend less than 60 if you look around. I got my hei for $20, and the difference in driveablity is like night and day. The starter barely cranks and it starts right up. The powerband seems wider, and the low end torque seems much "gruntier". The mileage is also improved.

This article helped me alot
Or you could just get a pertronix ignotor (fits right under the cap where the points were) to replace your points for ~$70.  It gives you electronic ignition. I noticed all of the above noted gains with it and a 40k volt coil (~$100 for both).  The DUI just seems too expensive.   Vintage performance,
had the best price I could find.
-Brian :beer:
i used the petronix and it worked great but i switched to the
dui and i am glad i did better lowend tourke better acc.
the dis is vac adv. not vac ret. this made a big difference.
when you order they ask you questions like what carb what exhaust etc.
50,000 volts i also got a set of there wires.
put it on two years ago set the timing and havent touched
it sence i highly recomend it.
I've got a DUI distributor for sale if anyone is interested, just e-mail me if interested . I loved mine, it was worth the money. After sitting for 3 weeks all i would have to do is pump the gas twice and then crank it and it would start in 2 secs, ran stronger to.
Robby Pate
So after reading everything here, talking to friends and mechanics, and knowing that I'm a poor bastard, it looks like the HEI is the way I'm leaning (unless ToyotaFanatic is selling that DUI for really cheap) does anyone have a list of any kind as to what Chev vehicles have the HEI?
And any tech links or instructions (the link ScottFJ40 posted kicks butt, but I don't think it goes into enough detail).
Pretty sure its any chevy in-line six with HEI. I read somewhere that someone used a '79 Nova I believe.
You want to look for a HEI with the vacuum advance port, if it does not have one, you'll need a computer to control it, and you really don't want that. I got mine out of a '80 chevy PU. Followed Jeremy's article in the tech section of IH8MUD and it works like a top. Better starts, wider powerband, etc, etc.
Scrounge and you'll save a lot of money.
Ed Long
I'm running the DUI along with TBI on my 2F. The distributor is NOT a modded GM unit. It is built from a cnc machined base that was designed specifically to fit the f and 2f motors. Besides the exact fit, the advantage is that DUI will tune the advance to your specific motor combo. Is it worth the coin? Was for me! Oh, don't spend for their wire set, get some from any auto parts and save $$$.

The biggest advantage most see from the HEI conversions is the added power. This isn't directly from the higher voltage spark, but from the additional advance the HEI offers. The DUI (mine anyway) is curved to bring in 24 deg of advance at 2000 rpm. With 14 deg of initial adavnce, this is 38 deg total. About 15 deg more than a stock dist offers.

You must have a ported vacuum source to use one of these distributors. Or for that matter a GM HEI conversion.
You must have a ported vacuum source to use one of these distributors. Or for that matter a GM HEI conversion.
Does the vacuum line that runs from the VSV on DS fender well to the stock dist. work? ('74 F and a half)

Users who are viewing this thread

Top Bottom