Challenger, 3400#'s, trans. brake, ladder bars, 6:20's equals a bent braced 8-3/4 housing.....it now has a 4-link and a Dana!

If your running high 11's, low 12's and so on....you should be fine with an 8-3/4 but like "scratchnfotraction" said, back brace it & go... If your going to use an 8-3/4, I would definitely brace it. Ladder Bar cars are real hard on rear end housings more so than 4-link cars and if your just using super stock leaf springs & or Cal Tracs or something like that, a braced 8-3/4 should be fine.

One more thing....the shorter the housing, the stronger it is and less "likely" to bend.