Running (2) HEI ignition modules ~ Wiring diagram?

[Petty43]

Does anyone run two 4-pin HEI modules wired to a switch to change from one to the other in the case of a failure? If so, are you only switching the Coil (+) wire, and the other connections are wired. This would only require a single pole / double throw switch. Thanks

[stock car driver]

I would not run a hei unless the rules mandated such. No comparison to the output of a msd set up with box.

[Petty43]

This is a project on a street car, wanting to be able to switch ignitions in the case of a failure.

[Lizardracing]

On street stuff, It's faster to change it in the car than wire up a secondary or better yet, have a complete dist ready to drop in. It would take me 5 minutes to change the dist.
To wire up a secondary you want a DPDT switch, each on a redundant circuit and you'll have to figure out way to cool the second module as it won't fit in the cap with the other.

[stock car driver]

Buy a good standard ignition module and dont worrry about failure, hei are simple they dont fail often even dirty parts out of the junk yard.

[racing08]

Stock Car Drive I run an IMCA Stock Car and have been running a DUI ignition would going to MSD be a noticeable difference?

[stock car driver]

08, I dont honestly think there would be a noticeable power difference. I spent many many trips to a chassis dyno especially in the 350 carb days, but I didnt compare them back to back as far as ignition. 350 carb I never ran over 6100 rpm.

I never in my life turned over 7000 rpm with my IMCA stock car 500 motors, if I hit 7000 at one of the 90 tracks I visited I changed my gears. Its my opinion that a hei is ok to about 6500 tops.

A external msd hvc coil would be a improvement over any in cap coil and it was too much for the hei type caps I was running. That was my experience. I burned thru a few caps and rotors.

I made a tester where I could turn the dist by hand and pull the plug gap back, it was two sharpened bolts. The hvc coil would go back to about 2 inches.... There were some really really bad coils, like the accel super coil was the absolute worst. Some junk yard hei were better. For a budget coil a STANDARD ignition old school oil filled points coil was the best.