Lee, my name is Chris Brown I own C & M Hydraulics all we do is remanufacture MBZ power steering gearboxes, p/s pumps, and air (smog) pumps with electro-magnetic clutches, we have been in bus. since 1994. The number you have is a casting number only. That casting will fit 107, late 114,115, 116, 123. The 123 box has internal stops in it, if you put any other box in a 123 the tires will rub on the brake track rod support. I can help you ID the box, give me a call if you like. 702.734.8090

Chris