GM HEI circa 1985 info needed

[Mike Morrin]

At 09:19 pm 10/26/98 -0800, Stowe, Ted-SEA wrote:
>
>hi, I am working on building a mutant Lucas/gm distributor for my mg tbi
>project.
>
>I have a '85 tbi system from a sunbird, which uses a HEI distributor.
>
>I have the matching GM ignition module which would of gone into that set-up.
>and I have a Lucas distributor which uses a hall effect sensor, which fits
>into my block.
>
>my problem is that the Lucas sensor has a 3 wires coming out of it, whereas
>the gm hall effect sensor uses 2. 

Did GM use hall effect?  I thought the HEI systems used reluctors, and do
not work properly if triggered by a square wave.

FWIW 

Mike