Big Block Tunnel Ram 660s Questions

What distributor do you have and how is it curved? Sometimes, some of the really light advance springs can pick up some mechanical advance at idle.
I am using a MSD pro billet ready to run. 18⁰ at idle and 38⁰ all in about 2000, 2300 IIRC. I am using vacuum advance and due to the 660 no having ported vacuum available, it is hooked to manifold vacuum.