Hi!

I have these 2 NOS small block distributors.

What do I have? Is the one with the single wire OK and useable in a high performance application? I assume this is basically the same as what MP sells.

What about the one with the dual wire? Is it a lean burn distributor? Is it useable in a hight performace applicatrion or is it junk? Can parts be swapped to work like a regular electronic distributor?

pic 1

pic 2, note the dual wires.

lean burns, at least the 80's incarnation on M bodies, don't have mechanical or vacuum advance in them...

Yep, those are both LeanBurn units with a VR sensor for electronic ignition. The 2nd one has 2 VR sensors in it.

I have heard conflicting info that:
the dual units were used in copcar applications, or in the later LeanBurn applications that also had fuel control via a feedback carb. (In those apps 1 sensor was used durign starting, teh 2nd one for after hte engine was running).

Or either statement could be true.

So they both are lean burn units?

How do you spot them?

No mechanical or vacuum advance is the clue.

I chekced my distributors again, and they both have the provisions on the case for the vaccumm advance. They have just been removed...

So based on this, they would not be lean burn units....

So, what are they?

Pretty sure you could use either in a perf app & for sure the single pickup one. You'd just ignore the dual pickup & open it's gap to get it out of the way then gap the other one to .006-.008" at the tightest tooth. Finalize your initial then use that figure to shorten the slots to get 35 total (vac adv unhooked if you are going to add the pod to the dist). You would want to toss the heavy spring w the long loop & sub in another which will take some experimentation to get the right curve then hookup the vac adv & work w it. If the pickups ain't exactly opposite pick the one that will give you the best rotor phasing (location)

From what I remember reading about that system, one pickup was for START and one was RUN. I don't remember the difference in timing between them. I've thought about trying to use one with an MSD with locked timing and put a switch to toggle between START and RUN. Not too sure if it would work. One of those backburner projects.