still tuning the smallblock. help please

[Benrs86]

now by playing with the timing i can get this smallblock with hei and a quadrajet to idle at 600 (idles rough though) and runs good. the problem is it runs so rough when i put it in gear it dies. also when im rolling up to a stoplight with my foot on the brake it dies. what do i do? what vacuum source does the vacuum advance pull from? there are 3 small ports on the front of my qjet and one on the passanger side. i am going to go redo the timing right now. someone told me if i disable the mechanical and vacuum advance it should be timed at 4 - 6 degrees btdc. is that right? i really need to get this running good to day. any help is appreciated, Ben