I think 40 days is Iran is a bit much. There are problems extending your visa, and not *that* much to see. I am sure someone will differ on this though - it is a matter of opinion.
Most people ride through Iran in a couple of weeks.
Similarly Pakistan doesn't demand 40 days, unless you want to go really off the tracks up the KKH - a pleasure no doubt.
Around the world 2000-2004, on a 1993 Honda Transalp