I have posted about my timing but now after reading post after post I'm not sure what connection on the passenger side of the carb to hook the vaccum line up to. Ported vs manifold what is the difference and which is best suited for a high out put small block 400.

This is a quote, taken from http://www.gofastforless.com/ignition/advance.htm

You're probably thinking, "Sure there is no manifold vacuum at WOT but aren't I supposed to use ported vacuum for the vacuum advance." Hold onto your hat, THEY ARE THE SAME THING! Except ported is shut off at idle. There are a lot of misconceptions when it comes to the ported vacuum source. After hearing 20 different theories I decided to hook up two vacuum gauges, one to manifold and one to ported, then drive my car and watch it. I found out they are the same, except the ported is shut off when the throttle is closed. Even then I had a hard time convincing guys so I hooked up a couple MAP sensors and a throttle position sensor to a data logger and recorded them while driving then dumped it into a spreadsheet and made a chart. As you can see, there is a direct relationship between throttle position and vacuum. When the throttle is closed vacuum is high, when the throttle is open vacuum is low, and ported vacuum is the same as manifold except when the throttle is closed. So which one do you want to hook it to? I prefer manifold vacuum. This pulls in more timing at idle which is good since there is virtually no load. Your motor will idle smoother and cooler with the extra timing. One night I was at the drags and my car was running hot in the staging lanes, I swapped the vacuum advance from ported to manifold then it would idle all night at 175°. Believe it or not the purpose of ported vacuum is to raise the temperature at idle, to lower NOx emissions. If you're like most hotrodders that is of no concern to you. If you have a big cam with a choppy idle then a vacuum advance hooked to manifold vacuum can really help. It will idle smoother and requires less throttle to maintain speed. Often a big cam requires you to open the throttle so far that the curb idle adjustment needles won't work. Hooking the vacuum advance to manifold vacuum will allow you to close the throttle some which may be enough for the idle mixture screws to work. Someone told me he noticed less dynamic braking with the vacuum advance hooked to manifold. I didn't notice it on my car but it makes sense. If the motor is running more efficiently with the added advance it will make a less effective brake. So which should you use? Try both and see which you like best.Here's the chart that was mentioned.
http://www.gofastforless.com/ignition/vacuum_chart.jpg

Neat chart, thanks for posting it, Fried Guy. I've said for years that the vacuum is the same except when the throttle is closed. They have to be since once the throttle is open they are getting vacuum from the same source.