Actually one mallory and one MSD in 2 months and the billet distributor got fried. Drove the car less than 300 miles and have had these three problems any guesses as to why?
I put the old orange box and MP distributor back on, how much performance will i lose compared to above?

Have seen people have this problem when the box is not grounded properly. They need a good ground...preferably to the battery negative terminal. Most people don't run it to the battery, but MAKE SURE you have a GOOD ground to the frame or chassis with good clean connections/terminals.

I ran a chrome box with MP distributor for years. Switching to MSD-6A with MSD coil, distributor and wires gained me nothing in et or mph. Looks neat under the hood, though.

There have been a lot of threads on MSDs and how finicky they are about grounds and a good battery feed.
I'd also suggest you look at your charging system carefully. This goes through the bulkhead connector and the ammeter, both tend to add resistance, causing the alt. output to increase. High voltage/current can fry electronics too.

Depending on your combo, a good mopar style ignition box will be fine.

I'd recommend an upgrade to a chrome one, or an aftermarket perf version like the FBO unit.

Depending on cam, you really only need the msd in the lower rpm ranges. Above 3k or so, it's single spark, just like a regualr moapr unit.

A good ecu will keep a straight curve with the distributor, no matter what brand name is on it.

Lesser ones, can't keep up at higher engine speeds.
I've spun several on my distributor machine. Stock units, start to fall behind around 4500. oranges between 5 and 6 depending on which one you get, and a chrome or an FBO will keep it together to 8k or so.

Sounds like your getting a power surge or have a bad ground.

What coil are you running? What voltage regulator - mechanical or solid state? What is the battery voltage with the engine running?

Running a relay would help too, i'm getting ready to install a streetfire box on mine, i may run a wire from the alt too the battery.

I say ground only because that was what I ran into. I had my MSD6AL box inverted upside down (which they say you aren't supposed to do anyways) behind my glove box applique right above the glove box door on a 70 Charger. I ran a 12gauge wire to a chassis ground. It made an odd buzzing sound but MSD said that some units do that, nothing to worry. It burned out one day and I had to buy a whole new unit. This time the guy at the speed shop said to mount it right side up and run a steelbraid cable from the MSD to the firewall. Never had a problem with it again.

I got rid of amp meter, did a volt meter and did the madelectrical.com conversion that everyone posted about. Since spring is coming i'm trying to figure out if i try the msd styled setup again or just leave the old MP system on.

I would call up MSD, they used to have great tech support and will repair you MSD as well.

As I mention on the other thread you may consider a capacitor.



From MSD...

If you experience radio noise after installing the MSD Ignition, you may need to install an MSD Noise Filter. Electro Magnetic Interference (EMI) is occasionally generated from the MSD power cables and can be easily eliminated by installing the Noise Filter on the heavy power supply wires coming from the MSD. When the MSD draws current, it will draw through the Noise Filter instead of directly from the battery, so all other accessories that operate off 12 volts, like the radio, fuel pump, or the engine computer, will be unaffected by the MSD. The Noise Filter will also prevent damage to the MSD during jump-starts and will keep a vehicle's 12-volt line clean by removing any voltage and current surges that could interfere with the operation of some MSD accessories such as the Soft Touch Rev Control or the Two Step Module Selector. It is recommended that the Noise Filter be used on installations with the MSD 7 and 8 Series Igni�tions to prevent this interference.

http://www.jegs.com/InstallationInstructions/100/121/121-8830.pdf