OK, I've changed my vacuum advance over to the ICM type and just want to make sure that my " initial timing" correct for my spark tables.

I have an inductive timing light and set my engine to manufactures spec's. (9 deg. btdc at 1600) Now I let the engine idle or curb idle(if I understand correctly) about 650-700 and take another timing reading ( 5 deg at idle ) while moving the inductive dial up till the timing mark reads "0" , the T light indicator is at 15 deg's....according to timing light instructions this is "initial advance" but which do I use for my spark tables??? The curb idle or 5 deg or the inductive reading of 15??? I am using a 4288 / AO bin for a 6 cyl and the 15 deg is close but I want to make sure before I start setting table up.