So I’m new to the forum and have a question that’s probably been answered before. I have a 1985 d100 with the slant 6 lean burn system. I want to convert back to a vacuum advance distributor and I believe I found a setup on EBay. I asked the seller if it would work for my application and they said that it would not work. It is advertised as a conversion from a points ignition to electronic but it seems reasonable to think that it would work for me as well as long as I change the carburetor to an older generation as well. I appreciate any help you guys would be willing to offer me.

You want to convert to the HEI retrofit desribed HERE

It is actually far simpler to convert a vehicle originally equipped with a lean-burn system to HEI than it is to convert a non-lean burn equipped vehicle.

First, on a lean burn vehicle you can completley ignore the portion of the HEI instructions dealing with a ballast resistor. In fact, all you have to do is get a standard electronic ignition distributor, a carburetor that has the correct ported vacum advance, an HEI module, the wiring, and the terminal. A realy is highly recommended, but not absolutely necessary (but still a very good idea).

You can wire it up two ways. First way: wires to the distributor, and use the + and - coil feeds to provide the + and - feeds for the HEI module. Second way, wires to the distributor, use the + coil feed to trigger the relay that powers the HEI module and use the - coil wire for the HEI module.

That's is. Alternatively, you can use the fat black wire that provides + feed to the lean burn computer to power the HEO module or trigger the relay.

It is also highly recommended to upgrade to a E core coil such as those found on Ford products in the late 80s to mid 90s.

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Casually looking for a Clifford hyperpak intake for cheap.

Hi Reed and thanks for taking some time to help me out.

So what year should I be getting the carb and distributor from? Mid 70’s, or any distributor with a vacuum pod will work?
Can I remove all of the other vacuum lines, electrical connections, vapor can, egr and also the ESA at this point too? It doesn’t seem like they would have much if any use once I’ve made this conversion correct?

I would look for the best condition and latest model carburetor you can find. Hopefully a Holley 1945, but a Holley 1920 would work, too. You need a standard electronic ignition distributor with a vacuum advance. Try and get one from a truck or van to get a timing curve closer to optimal for your van.

I do not recommend removing ALL the vacuum lines. Some you need to keep, such as the charcoal cannister lines and the PCV valve. Additionally, if your van has AC there will be a hard plastic line that attaches to the vacuum tree on the #6 intake runner and provides the vacuum to operate the various doors in the HVAC system in your dash.

Before you go disconnecting or removing things, I strongly recommend you get a factory service manual for your van and identify each part and what it does. Don't remove things based on your assumption of what they do.

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Casually looking for a Clifford hyperpak intake for cheap.