Has anyone tried a GM HEI module for a switchbox

[Yepblaze]

Has anyone tried using a GM HEI ignition module in place of the (up to, or more than) $500 OEM counterpart used on mid to late seventies battery driven CDI Thunderbolt ignitions?

I've been using Rapair CDI 114-2986 but they don't live long, even with a voltage regulator added.

I'm thinking I could just remove "their" little swichbox and attach my $20 part.

I'm not sure how to treat the pickup in the dist as it may be optical rather than hall effect.

 

[Laddies]

Re: Has anyone tried a GM HEI module for a switchbox

Yepblaze, the battery CD is fired by the Hall effect it senses any battery pulse in the system. I am somewhat surprised that your having trouble with the CDI components. Normally the only 2 things that give the system a problem are low voltage, alternator not working properly or a voltage spike from a bad connection,wire or even a battery connection.

 

[Yepblaze]

Re: Has anyone tried a GM HEI module for a switchbox

I've been through a pile of em.

I'd rather have OEM new, but right now this is something I'm considering trying.

I've got a couple old nearly dead CDI ignitions, and enough of a used dist to maybe set up a test bench.

Can I trigger the module from the merc and it's three wire optical dist?

Were all GM four pin HEI hall effect?

As another option,
What other brand/make (s) used optical mechanical adv dist and used a cheaply available module?

 

[Laddies]

Re: Has anyone tried a GM HEI module for a switchbox

I am not familiar with GM's HEI ign, but think it and the Mercury Driver system may be similar in the triggering aspect