I bought a used 12 bolt 3.42 posi rear and installed, was recently rebuilt and gears looked good. I never drove this gear ratio so I have a couple questions. On highway doing about 65 or 70 if I step on it to pass someone it accelerates real good but when I let off the gas it feels like it wants to slow down or downshift alot more that my old 2.73 gears non posi is this normal?, also upon acceleration it sounds like its spooling up, Im not sure if its the rearend or the new aluminum driveshaft?

 

Gear noise and drag..