I just bought a Saab T3 Turbo From "yardy8301"... I thought that i was a .42.48 but when the turbo came, i was inspecting it and seen that on the Compressor it has stamped... a/r .42 and on the Exhaust housing its has stamped a/r .63... Is this right?

 

it is possible, but it didnt come from the factory that way. some one prob just switched turbine housings

 

nope it must be some serial number or somthing.

if it is off a saab it is a .42/.48

 

agreed...saabs are .42/.48...many factory turbo cars us these ar's...
unless the car belonged to someone who modified the saab...which
would be a nice sleeper...