So I havent driven the dart much in the last couple years, been doing bodywork, paint, and re-assembly.

Anyway, its all back together and i've been driving it a bit, and it just seems gutless, no power. So I went to check the timing just for the heck of it. Did it like the book said, pull the vacuum line and plug it then check timing. Hooked up the timing light and the marks were showing about 10 degrees after tdc.
Also weird, the book says when you pull the vacume line and plug it, there shoudn't be any change in idle speed.
When I pull mine and plug it, the idle drops significantly and it runs a little rough.
Anyway, I set the marks to about 2 degrees before tdc. Book says 0, but at 5000 ft altitude we always go a couple degrees advanced.
So shut it off tighten everything down hook the vacume line back up, Start it up and it runs like crap, very rough idle, like of like it had a big cam or something, and it does not.
So I move the dist back to were it was before I started (approx.) and take it for a drive, was pinging slightly under a load, so adjusted just till pinging wasn't present under load. Runs pretty good, Idles well, car just still feels very sluggish.
So get back home put the light back on to see what it reads with the dist in this "road tested" setting.
With the vacume hooked up, it reads about 5 degrees after.
With the vacume disconnected and plugged it reads about 20 degrees after ? WTH?
Am I doing something wrong? Or is it possible that the outer ring of my vibration damper has spun and the mark is no longer were it should be?

Heres my setup
68 dart 2-door
71 318, bored 30 over, 9:1 compression pistons,
Edelbrock performer manifold
Edelbrock 600cfm carb
340 auto camshaft
early 340 exhaust manifolds
dual 2.25" exhaust all the way with walker quietflow muffs
mopar perf electronic ign
904 automatic
3:23 Gears.
Car just feels like a slug, especially off the line.