I realize this thread is 13 years old but I think manifold vs is ported is one of those topics that will always be hotly debated. I recently dropped a new MSD ready to run distributor and began reading/watching the endless forums and videos to see “which one is best.” From Centerville’s tech notes to Uncle Tony to the Buick manuals and also Buick owners. Each had legit reasons but in the end I opted to use the butt test. My 401 ran ok. 2-3 turns to start cold, solid 17 inches of vacuum, etc. It has a Demon 625 cfm that always had advance hooked up to ported. I noticed my vacuum advance was not holding any vacuum when I tested it and switched the knock off MSD with a real Nailhead Ready to Run distibutor. I curved it according to Russ Martins recommendation and boom! Big difference right out the gate. Immediately fires on the first turn, smoother running. Very eye opening. A little vacuum gauge tuning on the carb and timing had me pegged at 19 inches. This is where I started to wonder about trying VA off the manifold. So I did, and there is a significant change in the “feel”. PROS: The car snaps as you accelerate from stops, (small chirps from tires if I am turning from stops), runs a little cooler on idle, and begs to open up on the freeway. Just to make sure I switched back to ported and it mellowed out the acceleration and seemed lazy. CONS: noticeably rougher at idle when in gear (stoplight) or when shifting at low rpm (parking lots). I also smell more fuel from the exhaust on occasion so I presume my fuel economy will be slightly lower. Don’t care…this old cruiser will stay on manifold vacuum from now on. So I guess you just have to apply what works best for your ride and trust it. You know her best and tinkering is part of the fun. Good luck!
