1976 440 school bus engine - any good?

Well, it depends...
Would a '76 440 motor be a good starting point for a race motor? Found one for sale locally.
What do you mean by 'race'. For a guy like me, that might be a big hydraulic can and a basically stock longblock that's used in a mild bracket car. One of the seventies 'smog monsters' ought to be okay.

For higher performance levels, you might want to ditch the cast external balance crank (easier dampers and convertor balancing; crank is a little tougher).

The block is reputed to be one of the better ones.

http://440source.com/blockinfo.htm
http://www.arengineering.com/articles/sonicbig02

I think a lot of guys start moving to aluminum main caps and stud girdles when they get north of about 600 HP.

-bill