8 3/4 differential swap issues...

I have a 67 Dart 340, 4 speed with a transplanted 72 engine, 4 speed overdrive, and differential. The differential pumpkin is a 1820657, a C body diff (58-64) with 3.58:1 (yes, I said 3.58) gears, an open rear (non-sure grip). Wanting to put a sure grip, I bought a 489 pumpkin with 3.55:1 gears at E-Town last month. It was possibly rebuilt, and had reasonable tolerances. After it was installed the axles would not go in all the way, most likely the clutch splines not aligned in the 2 cone style clutches. This was fixed by locking the drive shaft and forcing the cones to slip by turning the axles until the splines lined up and the axles slid in all the way. But, now the axles bearings are not tight, even with the right side aduster maxed in, as if the bearing race is in farther than before. The bearings were fine before the changes were made. The the axle seals were changed, as were all the gaskets. Any suggestions. :sad5:

Thanks, Chaz.....