Use 111110 for the 8X16 (bus 3/4 means the trunks will use Bus 3 and digital sets will use Bus 4, that's why having your ADID8 on Bus 3 should work, it will use the last 2 offsets of Bus 3(offsets 2 and 3).
Give it a try and put your ADID8 on bus 3 as well, the dipswitches should be set to 101110 (Bus 3-offset 2/3).
If it doesn't work use Bus 5 for your ADID8 (111100).
Let us know the result.