@Obi,
Day 1 - Nairobi- Moshi - 360Km
Day 2 – Moshi - Dar - 560Km
Day 3 – Dar – Tunduma via Morogoro,Ipogo and Mbeya – 1020
Day 4 – Tunduma – Kapiri Mposhi – 800Km
Day 5 - Kapiri Mposhi – Lusaka via kabwe – 130Km
Day 6 – Lusaka - livingstone via Monze and Choma – 490Km
If you are a road warrior, you can reduce travel days by 2. The trick I used then was to tail a Scandinavian bus out of Dar all the way to Lusaka. A second driver is a must if you are to make it and the trip is not for the faint hearted

but it’s worth!
NB
I have given a rough estimate of distances, You would need to confirm the actuals but I don’t think I am far off .
Nothing great was ever achieved without enthusiasm.