I've got Dual Holley 6109's (750 Double Pumpers) with mechanical secondaries.
My jets are around 70 Primary and secondary
My cam is pretty mild also (.542 lift 306 duration)
and YES! Tunnel Rams do like lots of Advance to idle right.
I'm going to have 5 degrees advance taken out of my distributor soon. That way I can still idle at about 12 or 13 and rev up to 38 degrees total.
Hope that helps...