I hope I didn't come off as looking like I was saying "it's your
fault the bus burned!".  There is very little that SF could be
responsible for in an engine fire when all they sold you was a
longblock, though.  The fire almost certainly started from a fuel
line, whether from the line coming loose, being rubbed or pinched
through, etc.  There are a lot of connections in a dual carb setup
and each connection is a sourch for a leak.

I am sorry you lost your bus, and thankful you and your family
were not injured.

I always carry two fire extinguishers with me in my bus, they are
the cheapest insurance I can't afford to be without.

Good luck finding another bus.

Dave