bb into a truck with od

There is no factory bell housing to mate an OD trans to a big block. Lakewood makes a bell that will work but its a little spendy, or you will have to have the input bearing retainer machined to fit a big block bell.

Brewer's advertises a BB truck bellhousing with the 5.125 bearing diameter.
http://www.brewersperformance.com/proddetail.asp?prod=BH272
But likewise, not cheap at $399.95, well it's not cheap in my book anyway!