Looking for no BS info on 8 1/4 rears

i would like some info too. I heard from a mopar tech that the rears in the Dakota, Jeep cherokee and the like is a 8 1/4 and that the shurgrip units and gears will work if you use everything. I'm gonna run a 8 1/4 out of a 74 318 dart swinger. I wanna find a set of 3:55's with a surgrip eventually.