I recently picked up a NOS Duraspark harness for a mid 1970s E series 4.9 pretty cheap. Unfortunately I think it's a Duraspark I harness after researching it. Can I get a Duraspark I harness to work with a Duraspark II setup on my 86 4.9? I'm planning on doing the conversion once I get settled into my new house finally have a heated garage lol. I just wanted to know if I needed to hunt down another harness or not.

 

I don't know the difference between I and II. But the difference between a van and a pickup is that the wires are different lengths because the engines are in such different places with respect to the firewall/instrument panel. I would start looking for the correct harness.