So I just picked up a nice 72 Duster with a 440 swap (unknown internals) Seems to have what sounds like a 280-ish advertised duration cam, Holley Street Dominator intake and an Edelbrock carb. Bottom end is said to have flat tops and 452 heads.

First thing first the car needs some tuning as it has a nasty stumble on the bottom end (lean I think) and I noticed the Vacuum advance is not hooked up.

With the vacuum adv. not connected to a vacuum source, does is it run at full advance all the time or is it retarded all the time?

I have only had the car in my possession for less than 36 hours so I have lots to learn about it. Long term, I'll build a 512 for it that will be a bit more hot street orientated but for now I just want to get this thing running better with the parts that are bolted to it.

Thanks in advance