[77 TRASHCAN]

Helping a friend out. He bought a 71 Chevy C-10, been looking for a suitable candidate for a long time. You either find one that needs scrapped for $5000.00 or a primo example for way more than it's worth.

I assume this dist needs 12 volt power source. I'm asking about it because the previous owner usually took shortcuts, doing anything! It usually starts up, seems rich. Throttle response isn't bad OR good. Thankfully has a Quadrajet on it, number 7045583. My buddy is thrilled with how it runs and drives, I am NOT. He's not desiring an all our Hot Rod, just a nice driver, like a stock 71 would be. i think I have enough left over Cliff parts to help the carb (throttle bushings, and acc pump seal). We will see.

[Lee]

NOT 12 volts - you'll blow the magic smoke out of the module, at 12.

It needs a resistor, I think 9 volts max - google should provide the exact specs.

I ran a Unilite from about 1985 until around 2011 or 12, in my Cutlass. Performed flawlessly for well over 100,000 miles. Only reason I pulled it, was for an LS swap.

I'd disconnect the plug to the distributor whenever I welded on the car, to be safe.

[77 TRASHCAN]

I've found diagrams with and with out ballast resistors, concerning the 12 volt question. Not sure which coil it has, internal ballast resistor, or not...will find out...

[steve25]

All the Unilite's I ever used had to have a resistor and there use on the street without a vacuum advance in a pick up is going to hack into the drivability and fuel mileage of that truck.

[Lee]

Originally Posted by steve25

All the Unilite's I ever used had to have a resistor and there use on the street without a vacuum advance in a pick up is going to hack into the drivability and fuel mileage of that truck.

The Unilite I used had vacuum advance.

[77 TRASHCAN]

This one does have a vacuum advance, surprised me, I know the previous owner, a good guy, just a less than knowledgeable mechanical person..

I was more concerned about the voltage situation, wanting to make sure he didn't hook up a reduced voltage source, where it needed to be 12 V.

P.O. said he put a fair amount of miles on it, you never know the complete story...

[JLMounce]

I had a unilite on my bird previously and it worked well as a stand alone ignition. It didn’t have a vacuum advance with it however and couldn’t keep the car cool enough to keep the fuel from boiling in the carb.

Had to retire the unilite when I made the switch to my FiTech. It’s tach signal is dirty and doesn’t play well with those EFI systems. That would really be my only concern. If your buddy has no intention on going to an aftermarket EFI system, I’d run it.

Mine did also have a 9v ballast resister with it.

[1968GTO421]

Originally Posted by Lee

NOT 12 volts - you'll blow the magic smoke out of the module, at 12.

It needs a resistor, I think 9 volts max - google should provide the exact specs.

I ran a Unilite from about 1985 until around 2011 or 12, in my Cutlass. Performed flawlessly for well over 100,000 miles. Only reason I pulled it, was for an LS swap.

I'd disconnect the plug to the distributor whenever I welded on the car, to be safe.

I had a Unilite in a Stude w/ 350/350. It did well. no easy way to modify the mechanical advance without special Mallory tools; did have vacuum advance. Mallory really emphasized using the GM resistor wire or the ballast resistor that was in the Unilite box. Lee is very correct about both that 12V will blow the unilite module and that you need to disconnect the unilite when welding or poof no more module

[Joe's Garage]

And they were primarily intended to replace points distributors.

So the factory setup being replaced would either have a ballast resistor or a resistance wire already. I think the complete distributors might have even come with a ballast resistor in the box - I'll have to dig one out and look.

I ran a Unilite conversion in a stock GM distributor on my first 1973 Firebird for several years. Never had an issue until I ripped one of the rear sway bar mounts off the frame (testing out the adhesion limits of my new 255/60ZR15 Goodyear Wingfoots) and had to have it re-welded. Didn't know to disconnect the module while welding. It quit a couple days later.

I had a buddy who killed one by leaving his ignition key in the 'ON' position for about an hour while working on a stereo system. That smoked his module immediately.

I think everyone who ran one for any length of time kept a spare new module in the glovebox. I know I did.

[Kenth]

https://documents.holley.com/mallory...7_38_45_47.pdf

https://documents.holley.com/frm3441...tions_revb.pdf

[Formulas]

On a original points engine you have a wire going from the starter solenoid to the ignition so full 12 volts are provided during cranking for a quick start as soon as the starter is de'energized then the resistor wire coming from the firewall/ ignition switch takes over for running..

For a unilite you want to disconnect that crank wire from the solenoid and you want to test the voltage at the run wire to ensure it's in spec. and go from there.

Rev up the engine during this check to ensure the alternator is energized, remember some older cars the lights dim at idle?

If the running voltage is in spec randomly throwing on another resistor in there won't help anything

[cdrookie]

I bought a new Mallory Unilite system years ago. It came with a ballast resister, I didn't use it. I had it recurved by Larry Rowe, he said next time get a MSD or use the HEI, they are way easier to recurve.

[Formulas]

I had the unilite points conversion and burnt the infrared light out doing a compression check that's when I learned about cranking and running voltage in a points system because of the excessive time cranking the unilite could not bear the strain of full batt voltage

Now a full blown Mallory unilite distributor -->MAY<-- have input voltage protection built in

[hobbygto65]

They take a resistor wire or ballast. They don't take kindly to booster type battery chargers.

[PAUL K]

I prefer the Comp 9000 over the MSD. Also like the Unilite's with the vacuum advance.

[chevymad]

Ran one for years until it quit on me an hour from home. Discovered nobody within driving range stocks a module. It was a week wait for a new one from Summit. Ended up having to drop an old points distributor in to get the truck home. After that, whatever I bought either used a stock module or I kept a spare.

[Cliff R]

Yep, that's the deal with ALL of these aftermarket distributors and points replacement units.....they ALWAYS take a dump sooner or later, but they NEVER quit when you are out in front of Jegs or Summit Racing........LOL.....

[Formulajones]

Originally Posted by hobbygto65

They take a resistor wire or ballast. They don't take kindly to booster type battery chargers.

Something related to that, If you need a jump at some point, plan on possibly putting another Unilite in. Every time my buddy ever jumped his car, it would fry the Unilite.

I never really trusted those things, or any other style of retrofit module in a distributor for that matter. To each his own.

[Formulajones]

Originally Posted by Cliff R

Yep, that's the deal with ALL of these aftermarket distributors and points replacement units.....they ALWAYS take a dump sooner or later, but they NEVER quit when you are out in front of Jegs or Summit Racing........LOL.....

And that's really hitting the nail on the head for me. I tend to not install things on the cars I can't get relatively easily, or at least rig around it to get it running. Especially since my wife and I depend on these old cars for daily transportation.

Doesn't do much good to have a unique part, especially ignition related, if it can't be bought at any local store.

[PAUL K]

Having seen other guys burn up their modules I acquired a good spare and put it in my glove box. I haven't needed it for thirty years but I'm sure if it wasn't there I would have. Same deal with electric fuel pumps, the OEM guys were pretty good.

However I remember burning up a HEI module a few times on my original 301. When I finally carried an extra in the glove box never burnt another one.... Ran fifteen with the HEI and nines with the Mallory.