I had an original 3.08 posi, put in a crane cam, = to TA 212 and my brother said "I thought you put a cam in. Put in a 3.90 posi and you talk about this new Woke crap, that 3.90 was the answer..... Eventually a 4.10 Eaton with a 2004r 4 spd overdrive finished the pkge.