So don't start with me trying to fix my Dash vents not blowing any air trying to find any vacuum leak so I came across one for the old heater valve letting my research trying to fix that I've come across which Port I should use for vacuum advance and I don't know what would be best for my car has a 292 cam vortec heads reworked it' a 355 i have a holley street demon carb 625cfm that' all I know about it and I don't know what ports and hoses I should use

 

I personally like full time manifold vacuum.

Here is an article written by an GM engineer on why they switched back in the day

http://chevellestuff.net/tech/articl...r_manifold.htm

Another from super chevy

http://www.superchevy.com/how-to/add...nition-timing/



Although in the end do what makes your car run better.