annoying miss at idle, ideas appreciated

Have a rig with a 200/I6 I was told it was from 1969, but I'm not sure.

Have been battling a series of unpleasant carburetors.. Finally found a actual new 1 bbl.. Installed.. Aside from having to convert to a manual choke still, it seems to be a good unit..

HOWEVER: it still has a rough idle, a miss at idle and constant speeds.

I put in a Pertronix ignition, new cap, rotor, and coil (was very old)

I would appreciate any leads?

One issue that still confuses me is the SCV (spark control valve) and the appropriate distributor.

Pics below show the distributor.. The carb on there HAS a SCV.. Should it?

[img=http://s5.postimg.org/rlydz2a4z/dist33.jpg]

Unfortunately can't tell much from your distributor picture, an inside view would be much more helpful. That said here are the basic rules for proper LOD operation.

1. A LOD type distributor will need the proper carb to work, one that has an SCV.

2. A carb with a SCV can not be used successfully with a non LOD type distributor.

3. The bottom line is that the wrong combo of parts can't be tuned correctly!

To learn more about how a LOD system works (it is different from other systems) you can read all about it in the excellent article in below link. Also have you done a compression test yet there are a number of other causes of missing. Good luck

http://classicinlines.com/Loadomatic.asp

Sounds like you do have an LOD distributor then! So to answer your previous question yes your carb needs to have the SCV to work correctly with that distributor. Good luck

Thanks! Im attaching pics of the dist and carb, id love verification that the two are indeed compatible? Much appreciated!

Yes they are! Make sure that the vacuum canister on the distributor is operational, i.e. Moves the breaker plate and holds a vacuum. Set the plug gap at .035 to .045 this is dependent on how hot a coil you installed along with your Pertronix. With an auto trans you want to set base timing to a min of 12 degrees, set you carb mixture screw to the lean best idle, then set idle RPM to 475 - 500 in Drive with parking brake set. In your above list of new parts you changed you didn't list plug wires if they are bad they can also cause a noticeable miss at idle, if you have a volt / ohm meter you can test their condition or replace them. Good luck

Do a compression check on the engine. All the tuning in the world won't overcome a low compression miss. To know what year the block is look at the casting number on the block in front of the starter. First 2 letter # is year code C= 60s 9=year so C3=63 C9=69 D2=72.

Quick thing to check: Are your spark plug wires in decent shape? Are they solidly connected to the plugs? I had one plug wire that wasn't seated properly on the plug. Caused the engine to run rough, especially at idle.