[PsychoBillyCadillac]

Wow,
Thanks for all the suggestions guys, some of these I would not have thought of. To describe the "shudder," when the engine is at idle it looks just like someone has it by the manifolds and is rocking it from side to side very quickly, you can feel it vibrate throughout the car. When you rev the engine, as the RPMs drop back to idle it gets worse for a moment and then goes back to a steady shaking. Under the hood it is quiet, there is no ticking or knocking at all, but if you hold the throttle part way you can hear a faint ticking through the exhaust which mirrors the shaking. I didn't fool with the points/condenser when I did the engine re-build as the car was running well prior. I have never changed a set before so can someone tell me what to look for if they are bad and how to go about replacing them if they are? I know some engines do strange things if the points are out of whack so I think I will try that approach next and see what happens. THANKS!!