Need a new ignition module

[77 K20]

I have went thru 2 of these in the last 2-3 years:

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It is a MSD ignition module that fits inside the distributor. This was the "cheap easy route" for me to go as my fuel injection unit needs a digital square wave for the tach output. They are "only $115" or so... Simply grabbing the tach signal off of the coil isn't good enough.

The first one died within the year warranty. They replaced it. The replacement lasted about 1.5 years and just left me stranded about an hour ago. I'm pissed.

What other options are there? A MSD box on the firewall? Which one? Are they reliable? Are there any other companies worth looking at?

 

[77 K20]

I"m looking at this one so far-
MSD DIGITAL 6 OFFROAD IGNITION

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[MikeB]

Wow, I've had an MSD HEI module in one of my engines for at least 15 years. Of course, that's back when they were made in El Paso. I'm not sure where they are made now.

Are you getting full battery voltage to your HEI distributor -- somewhere around 13-14 volts? Also, what spark plug gap are you running? I've read where anything over .045"-.050" can be hard on modules.

As for an ignition box, the old 6A series was very reliable, so I would hope the new Digital 6 series would be even more so. Do you need the features on the Digital 6 Offroad?

 

[77 K20]

Yep, full battery voltage.

AC Delco plugs, R44LTS gapped at .040 (as per GM's crate motor instructions)

I verified there are good grounds everywhere.

I like how they supposedly made the offroad one more vibration and water resistant. My truck spends most of its time in the dirt.

The display on it would be kinda nice. A hit of a button and it will show RPM or the battery voltage (that it thinks it sees). Could be handy for troubleshooting.

Or I just found this one:

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It "compliements" EFI systems. Don't really know what that means. The only thing my EFI needs is a clean tach signal.

 

[77 K20]

Ok, looks like the "offroad" one is fully potted where a lot of the other ones are not.

Potting should help internal components from breaking or cracking due to vibration.

Also can help seal against dust and water

 

[77 K20]

Finished up the MSD install today. Still need to go back thru and route the wiring better/clean it up.

I can honestly say it runs better an smoother than it did before. Maybe it is more "compatible" with my fuel injection. There isn't a reason why the old ones shouldn't have worked.

The display can show battery voltage or RPM.

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