MSD Ignition Module

[cabriolet409]

I am completing the wiring on my 34 Ford cabriolet with 409. I have been reading about MSD ignition modules (for example the 6A). I was wondering if anyone on the site has experience with them, and what the general concensus is regarding their use. I've seen a number of these on BBCs and SBCs at the shows, and even a couple on 409s, and wondered if they were worth the $200 asking price.

Thanks in advance for your help and expertise!:bow

[Thirdyfivepickup]

I assume by module you mean ignition box... 6A... 6AL

It all depends on your application. If you are just building a cruiser and not racing it... I'd save the money. They are designed to give hotter/multiple sparks throughout the rpm range. It helps in higher rpm applications as well as higher compression.

For the occasional blast down the quarter mile... you probably wont need it.

I had one in my El Camino and it ran 12.71 with a 6AL box and billet distributor. It ran almost the same (a tenth slower) with a GM HEI which could be contributed to atmosphere... traction... anything.

Anyone else?

[jim_ss409]

I used an MSD box mostly because I wanted a rev limiter. The car does fire up noticably quiker than it does with points and I think the plugs would be less likely to foul. Still, it's just one more thing to give you problems.:dunno
I think an HEI style distributor or a conversion like the Ignitionman does would also work really well. I used a Crane points replacement module in a stock distributor to trigger the MSD box and that seems to work well so far. The Crane unit has a built in rev limiter but aside from that I don't know if it's any better than a Pertronics. http://www.cranecams.com/index.php?show=browseParts&lvl=5&prt=1973

[dunhamfield]

I concurr that it is not needed if you are not racing. I am running GM HEI distributor and it does just fine.
One thing to remember though, make sure that you use #10 wire to supply the best voltage to the HEI.

[dq409]

OK,, I`ll be the different one here,,

The 6AL is a great investment even on a street car.
The 6AL has a built in rev limiter which in my opinion is cheap insurance.

The multi spark of the MSD unit also IMO, helps any engine run better.
I believe you get a more complete fuel burn.

I run the 6AL and an Ignitionman HEI conversion dist.

One more advantage to this setup is you retain the stock looking distributor and cap and can hide the MSD unit where it can`t be seen.
Thus you get the modern hot spark of the HEI, multiple spark of the MSD and keep the smaller stock looking distibutor.

I just think the GM HEI is BIG and UGLY and doesn`t belong on a beautilful engine !!!

,,dq

[cabriolet409]

Gentlemen,
Many thanks for the excellent advice! You guys are the greatest!:bow :bow :bow