Low Vacuum Issue/Big cam

Where do you have your vacuum advance line hooked up. Sound like it's direct vacuum. You need it on a ported advance nipple. It should have little or none in the way of vacuum through the line at idle. What will happen with a direct vacuum source, the vacuum signal drops and the advance goes away, it acts like a dog off the line

IMHO, 10* initial is not near enough with a 484 cam. Should be in the 15-20 range, maybe more. Take the vacuum advance line off and plug the port at the carb. Use a vacuum gauge to tell you what the engine wants. Picking a number and trying to make it work isn't the best way.

read this for setting initial with a vac gauge.
http://www.forabodiesonly.com/mopar/showthread.php?t=56694