I agree with Moper. I run a Detroit True-Trac, with a set of Strange SS axles (street and Strip) I have broken sh-t since putting them in, but it's not axles or posi. Like one fellow told me on a 4 spd sight, "super stock springs with adjustable snubbers have way to much axle wind-up and your going to break stuff". He told me to put the caltracs in and it will cut that way back. Automatics are alot different for all that are about to jump on me, defending there SS leaf spring set-ups. I ran low 11's on a 904 automatic for years on end with no rear suspension breakage. I have a streetable mid 12 second motor behind my 4 spd. now and have broke alot.