Does anybody know if an aftermarket adjustable vacuum advance will work with a DUI? Or possibly if the DUI is already equipped? I would like to retard slightly at high rpms near WOT and from my understanding this would make it possible.
I found this on Jegs. Its for a V8, is there one for us? Does it matter or are the internals of the shaft basically the same?

Crane Cams#271-99607-1
Adjustable Vacuum Advance

 

Not a DUI distributor, but I purchased a new Duraspark "recurved" distributor purchased from one of our sponsors and it came with a Motorcraft vacuum canister and is adjustable.

 

Not sure on if the DUI is currently equipped. You might want to contact Performance Distributors and ask them. They're generally really good about getting back quickly.

 

IIRC, the vacuum advance is adjustable with a 3/32" Allen wrench. Get one and stick it in the vacuum advance nipple and see if it mates with an adjustment screw inside.

 

At WOT there isn't any vacuum advance... It goes bye-bye when the go pedal gets mashed. It's entirely a function of engine load. It comes into play at steady cruise on the highway or going downhill.

 

Yup, my DUI doesn't bring in any vacuum advance until 8hg. WOT is going to be down near 0 - 1hg depending.

 

Or 2-3" Hg with the restrictive log intake and Carter 1 barrel.