Classic/Antique Car Repair: 235 1955 Chevy Engine, spark plug wires, new distributor cap

Question
I've installed this engine (supposedly was rebuilt) in my 49 Chevy.  The engine is running a little rough.  When I take off the 3rd or 4th spark plug wires, there is no change in the way the engine idles.  I've changes plugs and wires.  No difference.  I have a new distributor cap.  When I took the cap off after then engine has idled for several minutes several times over the last few days, there was "gold" flakes/particles in the area where the points and condenser are.  What does this indicate?  Could this be the reason I'm having trouble with the spark?  Any ideas of what I can try next?

Thanks.

Michael


Answer
My first though seeing as the two cylinders are right next to each other would be a vacuum leak in the intake manifold or a slight leak in the head gasket between the two cylinders. Spray carburetor cleaner around the area where the manifold attached to the head with the engine idling. If there is a vacuum leak the engine speed will change. If that is not the problem then a compression test is in order. The flakes in the distributor need visual investigation, but I think that this is another problem.
Brad