pushrod length ball to cup
some good info here:
http://www.pushrods.net/
it's smiths page
they are the best extremely reliable etc
they send you a tool to measure, then you send it back they make your pushrods perfect
they have lots of info up there too on the howto section. you can even make your own measuring tool (follow their instructions)
ask around, people will say use smith's pushrods