Will A MSD6A make much of A difference
over A mopar performance orange box
ignition.

I had been asking something similiar, and most people seem to think MSD is the way to go:

http://slantsix.org/forum/viewtopic.php?t=13013

MSDs are fine but expensive. They're not the only good ignition out there, and are large overkill for most street applications.

HEI is bettter than Orange Box, for a LOT less money than MSD, and has the added advantage of inexpensive replacement parts being available literally everywhere and anywhere.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

since I haven't been completely sold on any particular set up yet, I will do some searching on the HEI set up on this board.

I do admit my ignorance here, but when you say the MSD is overkill for street, can you say why? I assume it is based on how far people take their engine mods, but do you have a particular "level" in mind? as in, most people don't do enough of and upgrade in other areas to make it worth it? is that what you mean? like a stock 2 barrel super six compared to a full 4 barrel and headers kind of deal?

HEI conversion
The ignition's job is to light every cylinder, every time. That gets more difficult to do under very lean or very rich conditions, under very high compression, and under other extreme circumstances. here's the important key: There's nothing to be gained by putting in an ignition system that will cope with conditions you'll never encounter.

A points-type ignition system lights most of the cylinders most of the time, but requires a relatively frequent maintenance system to keep doing so. A Mopar electronic ignition works well, but the plug gap's pretty small and the ballast resistor is a somewhat common failure point.

The HEI module is GM's answer to the Mopar electronic ignition. It eliminates the ballast resistor and provides a hotter spark across a larger plug gap. Some of GM's engines in the mid '70s had absolutely awful induction systems and combustion chambers, which gave rise to extremely difficult-to-light cylinders occurring even in everyday driving. Rather than fix their substandard engine designs, GM designed a really nice high-performance ignition system to compensate when emission laws made reliable ignition of every cylinder mandatory, rather than optional. Reliability is excellent, parts are widely available and cheap.

It's not as sexy as a big red MSD box under the hood, but it works great and lets you spend the money you didn't spend on an MSD, on something that'll make your car go faster.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

slantsixdan I am running 100 nitros shot,
on A built /6 that runs 14.5 without the shot.
But I need to upgraid the ignition before I
start using the shot. So with that in mind
is the HEI going to perform as good as MSD.
Also how much difference is it going to be,
between MSD,HEI,and orange box to the
perforance of the car.

Ah, no, that's definitely higher demand than stock, so I take it back. Go get an MSD.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

hey! what about me? what is the cut off line?

Forced induction or NOS or ultra-high compression or a great big rumpety-rump camshaft might give cause to get an MSD. An HEI will dish out all the spark most any stock or near-stock equipment (basically any street-driven configuration) needs.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

okay, because I am running a clifford cam with .531 lift, (246 in. 256 ex. at .050) and the head is shaved .090.

have the usual holley 390 and headers too (need new headers).

An HEI is plenty good enough.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

okee dokee.

thanks for putting up with all of my questions.

Thank's slantsixdan, I ordered the MSD6A today
I let you now what I think of it in about 2to3 weeks.

I got the MSD on the car and it makes
a big differance conpeared to the orange
box. The car runs alot smoother at high
RPM(5900) Also there is a noticable differance
on start up, the car idles bether.