[DeTomaso] vacuum advance on Duraspark II systems

[Lee Farrell]

I just found out the vacuum advance on my D II ignition is unconnected.  (benefit of replacing the water pump???)   I have the stock blue strain relief, standard cap size system.   I found a web site which says this is preferred, but that doesn't seem right to me.   There is also an unconnected fitting at the top of my "basic 600 Holley carb".
Any comments on what is the preferred setup?
thanks 
lee farrell