The 6100M is a points replacement for a stock distributor. ...... http://prestoliteperformance.com/e-spark-replacement-module.html
The 605 is a replacement for a Mallory distributor. ....http://prestoliteperformance.com/replacement-unilite-module.html

 

Just got off the phone with Summit Racing tech support and the 6100 is basically a redesigned version of the 605. BOTH work in a Unilite, the 6100m is priced to compete with ACCEL parts.

 

I've got a unilite that needs the module. I was looking at the 605 and at $100.00 I said forget it. Now at $50.00 I may have a purchase to make. What's your thoughts on the unilite, are they good? I heard the module is easily burned out. ?????????

 

I'm running 3 unilites and the oldest goes back to about 15 plus yrs. Never a problem with any of them. Guess it possible but have never heard of them burning out.

 

The Unilite's are great distributors and need no maintenance the only downside to them is that the module is very sensitive to voltage spikes.. and if you run a ballast resistor this isn't uncommon. But Mallory makes what they call "power filters" to protect the module from voltage spikes. It plugs in easily in-line with your existing connector and costs $35, I'd say it's worth it not having to buy another module! I just ordered one with my new module from summit racing :sign0020:

Here's the link:
http://www.summitracing.com/parts/MAA-29351

 

Why would the resistor have anything bad to do with a power spike? It should help if anything (lowers the voltage) but I think the bottom line is it doesn't affect that kind of thing at all.

Unilites are OK for getting rid of points, but they won't give you a performance increase. You need a CD or inductive box to do this, but you can use a Unlite to trigger it.

The high performance setups use a magnetic trigger (like an HEI has) or a Hall effect trigger, along with a box as above.

But, there's a hundred ways to do all this, and most work well.

 

When Mallory suggests you unplug the distributor when working on any component in the electrical system, that's a bit too scary for me. MSD mag pickups and amplifiers laugh at this nonsense. I've been using their GM HEI components and ready-to-run distributors in my cars and buddy's cars for nearly 20 years with no precautions and zero problems.

 

Any welding, disconnect the battery cables.

Transient voltage spikes due to arc or other electric welding will kill a Unilite module, and can be hard on other electrics and electronics in cars.

Be safe, disconnect both battery cables prior to any welding. That includes a trip to the muffler shop. My muffler guy agrees.

Other than the aforementioned, the only Unilite module "problem" I ever saw personally wasn't a real failure. I don't rightly recall the make of engine, it could have been a Mopar, but the distributor somehow gathered so much motor oil, the eye in the module became obscured. Once discovered and cleaned, the engine lit.

 

I have had a Unilight in my 67 Camaro since JImmy was President. Now for the kicker, it has NEVER had a resistor other than factory res. wire. On my 55/56 I use 57 Ford resistors, not Chevy, a Ford has same spec as Mallory at 1/4 the cost. I got conned into wasting money on a MSD dist for my Z28 drag car. Buying a tach drive MSD lowered my bank account but did nothing for ET.

 

No amplification.

Buying a tach drive MSD lowered my bank account but did nothing for ET.

Truer word were never spoken, but the distributor itself is not to blame. Unless the former distributor was causing spark timing scatter, changing just the distributor will seldom help anything.

Robust spark energy comes out of a hangin' mother spark box. Then sometimes the spark plug wire insulation is rendered inadequate to contain the big spark, and the car runs slower.

It is a slippery slope. We have even had to ventilate a distributor cap, to remove the trapped ionized air caused by an MSD 7AL. Ultimately, we got the car to wake up and run stronger, but it was a learning curve.

BTW - MSD's literature covered each obstacle, we just didn't initially believe our situation applied.

 

I never have quite understood why you disconnect the battery cable and expect to protect electronics or electrical devices when welding.

Seems to me that the electronic box or device is still grounded to the chassis/body/engine and those are all tied together by ground straps or direct contact.

Then you connect up the welder, connecting its ground cable to one of those, and start welding. How does disconnecting the battery do anything? Your welding ground is connected to the same ground the battery was connected to. Any other wiring is separated from ground unless there's some defect (which should have been blowing fuses or melting wires prior to the welding).

What do you guys think?

 

I agree have done it without disconecting for years.