Dear Shams,
I drove a Ford Transit long time ago. Then the bloody Iran Iraq war was going on and I entered from Maku and then spent a night in Tabriz. From Tabriz till Tehran I found a pretty motorway which extended till Isfahan (probably). From Tehran Caspian Sea is just 150 kms and gorgeous, somehting you cant afford to miss along with local Caviar at dirt cheap price.
Then I spent a night in Kerman and the next in Zahidan.
You'l get lots of chilo kababs and free lessons in Persian which you should be comfortable whithin 2-3 days.
I am using my remote memory so might be a bit hazy at times. I hope it might give you a clue or two to your concerns.