i have a 77 250 with a 60 &70 under it and cant seam to keep a rearend under it. there are no bad angles,binding or spring wrap problems(rear ladder bars).i have destroyed 2 center sections on a 60 and snapped 2 pinions on my 70. my question is a gm 14 bolt any stonger than my 70? i have been told that they are but im not sure. i have access to another 70,14 bolt,or a 60.im tryingto get ready tomud race agin. any help would be appriciated.