[walker]

I will eventually see your burb somewhere. I see so darn many of our trucks, I just keep looking and looking.
As far as the vaccum advance goes that is a whole new raging war! I run mine off the ported port. This provides higher vaccum as the engine revs higher. If you install it on the other port the theory is that you advance then is only on the lower RPM range and goes away at higher RPM. I have put a vaccum gauge on my motor and have found that not to be true, at least for a stockish motor(no huge cam). The vaccum at higher RPM would need to be equal to or less than idle vaccum for that advance to go away, and that is just not the case, again for a stockish motor. Even at WOT the manifold vaccum is higher than idle manifold vaccum. There is a dip when the throttle is first opened but then it climbs up. I run a 1405 edelbrock on a GM crate with stock heads. So you could do what I did and put on a vaccum guage and a timing light and play with it to see what your engine does. It is an interesting exercise if nothing else. I am sure that many other people have many other biases in this area, there will be those who swear on way and the other, I just call 'em like I see 'em.
As far as an emission test goes, I would check you total timing(initial+vaccum+mechanical{unless you are of the school that is connected to the manifold vac port and believes that vac adv goes away with higher RPM in which case it is initial+mech}) and see that is not much more than about 30* or so. Connect the timing light rev 'er up and see what the total timing advance goes to. Might stop in at Lopers(I think checker even has it now too, in their speed shop area) and pick up a timing tape to make it easy to read totlat timing.
If you want to play with it I also have one of those Color Tune thingys you could use too. Let me know.