8.75 Axle - 741 / 742 / 489

Too bad you aren't closer and closer to swapping in everything- just pulled a beautiful set of 3.91, sure grip gears (489 case) from a '72 shorty 1/2 ton van with a slant six. Got them up for $435 obo...
http://seattle.craigslist.org/est/pts/3799750860.html