Originally Posted by slownrusty

The compressor housing actually will spin perfectly centered if you rotate it by hand on the large end where the it bolts to the center cartridge, the key is to just back off the bolts enough to spin the housing not completely remove it. I have done this many times, just requires care and patience.

I am running one of those new $$ Zero clearance hybrid Garretts on my old Turbo Z and I just re-clocked it using David (125 Shifter) suggestion.