Also your cam duration can play havoc to the timing if your not using the correct timing curve for your cam'
cams with less than 220 duration @ .050 =10 to 12 degrees of initial timing.
cams with less than 240 duration @ .050 =14 to 16 degrees of initial timing
cams with less than 260 duration @ .050 =18 to 20 degress of initail timing