My brother got this in a trade for some stuff he was just trying to get rid off. Its new with the remanufactured tag on it, he sent me these pics and the following info from the turbo tags:
Borg-Warner remanufactured for Mack Trucks:
Model S3A-035
P/N 631GC5123AP28X
S/N J2403 481 R9
Compressor cover stamping W50 G199
Exhaust stamping 7J24* 693411 DUC 258




Any info. appreciated.
-J