i have 3 rear diffs that i would like to get rid of, one 7 1/4 390 suregrip, one 8 3/4 open b body rear, it has highway gears (2:76-2:93, something like that) it's a 741 case and it doesn't have any perches on it, one 9 1/4 open w/either 3:73 or 3:55 gear, i was told that it came out of a lil'...