new engine problem

It is a 360 .030 over,eagle crank,rods,kb pistons step dished and milled to a acheive a quench of .035,J heads ported,cam is a comp 20-231-4. The marks on balancer are stamped not a tape. It always starts good,does not diesel when shut off and has around 12 in vac at idle. As far as total timing I just checked it and here is something strange,if I set total to 36 than base is also 36. If I set base to 40 than total is 40 with vacuum advance unhooked. I tried 2 distributors with same results. Poss module? is orange box now. This is being checked with both a normal and advace timing light with same results.