I have a 71 centurion convertible with a 2:93 open rear and I'm looking to go with posi and a 4:56 gear. I have been told that I have to switch rear completely since my chances of finding what I need for mine are out of the picture. I've already spoke with monzaz and he didn't have anything either. What rear would I need to look for to make this work?(posi,4:56) I was told a 73 impala rear would work or any 71-76 b body rear??? Any help would be greatly appreciated!!! Thanks
Chris, You need to look for a full-size posi 9 3/8 from a '71-76 Fullsize. Typially Centurion, LeSabre, Riviera, Electra will be a direct swap in. I've done it before on my prior '73 Electra. An Estate Wagon would work but since its a leaf spring axle, you need to transfer only the guts. Typical gear ratios will be 2.73, 2.93, 3.23 and 3.42. The board has covered this topic before, the search function will be your friend. See below: http://www.v8buick.com/showthread.php?263843-9-3-8-posi&highlight=9+3%2F8+posi http://www.v8buick.com/showthread.php?91387-71-riviera-12-bolt-posi&highlight=9+3%2F8+posi http://www.v8buick.com/showthread.php?160301-POSI-axle-for-1972-Boattail&highlight=9+3%2F8+posi Hope this helps. Let us know if you have any other questions.
