As we all know the 3.9 has a vaccum advance distributor, I'm kind of aware of how they work but mine on my d1 is plugged on the distributor and where I think it goes on the intake is left open. The truck runs fine no cel I'm thinking the unit stopped working so someone put a cap on the distributor. Can anyone explain exactly where it goes or give me a diagram? I can't find anything, also is there any issues with running it like this? Any and all help is greatly appreciated thanks Nate?

 

A hose runs from there up to the nipple on top of the intake manifold. You can run without it but you wont get that extra power on load.

 

IIRC the vacuum advance has two ports, one capped, the other on the bottom with a vacuum hose going to the intake.

 

Sweet! Thanks looks like I'm gonna test the vacuum advance part and make sure it works before I hook it up tomorrow! Thanks a bunch!