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.

Vacuum advance sounds like you have it plugged into manifold vacuum and not the timed ported where it should be?

you should be plugged into the vacuum port to the left of the PCV (large port)
instructions case you lost them right at the top of page 2.
http://static.summitracing.com/global/images/instructions/edl-1405.pdf

I assume you don't have a dial back timing light or marks on the harmonic.
Unhook and plug vacuum advance again.
Set it to about 5 before TDC and go for a drive forget the vacuum advance for now if it pings back it off till it stops if it don't maybe try 2 more degrees. if it's still fine go home set the in gear idle the way you want it helper in the car is a must.

"Now" plug the vacuum advance into the timed port (the one to the left) should make no change in idle drive around and see if it pings at cruise under light acceleration.
If it does tune vacuum advance back with 3/32 allen key in through the port on the vacuum canaster on the dizzy turning counter clockwise a turn or two at a time till any ping under light cruise load is gone and you should be good to go.

Good info guys, i'll try out some of your suggestions if I get some time sunday or monday and report back.

I know very little about this advance stuff so I may have questions along the way.

p.s. its a mopar perf electronic dist that I bought new about 10 years ago. Not an old one frome 70's
Thanks

Dodgem,,, your totally right about my vac advance hose. I've got it connected to the manifold vacume port on the carb and not the timed port.

Cant wait to try your other suggestions and see if I can get this thing running better.
Thanks

The car should still run fine with it hooked to manifold vacuum unless its way overadvanced. That aside it will run identical once on the road because the ported vacuum comes into play once the throttle blades are open enough to expose the ported vacuum slot, I.e once it's off the idle circuit. I'd suspect that your damner has slipped or is in accurately marked, or maybe the light is faulty.

For what it's worth my old 273 with a 340 cam liked 15 initial, and about 35 total.

Not to be a wise guy but you're sure you're reading before and after tdc correctly, right? Before tdc is further counter clockwise from 0.

try what I say and you will be fine. some bad advice to be found hear.

Are you just used to driving the daily mustang?

I just got my 340 six pack running ok - the timing mark is way off - so I assume the balancer has spun. I just sent a 340 balancer in to the damper doctor to rebuild, which I will install when i get it back. I am thinking if the balancer has spun - it is not good thing to keep it running in the car.

Not yours in this case save fore intial may be off as his does not start to advance till 1500! :-)

Time for a TDC check with a piston stop.

Glad it's happier to drive.

some dampers are made to use a different timing mark location on the timing cover.

i once did a 340 with a newer 1984 I believe cover and had to make my own mark for TDC.

you sure your on 1 Fords are all foolish in firing order.!

15 degrees clockwise (to the left) from the 0 mark would make sense 15 Counter clockwise (to the right) does not but could be the ring or timing cover.

will it pull the wheels now???