my first 742 case rebuild, need alittle advice please

so I finally got back to this last night and got my new races pressed in and 90 thou shim and bearing pressed on and put in the carrier I haven't checked the backlash or pattern yet but hopefully tonight, then it hit me... I don't have a spacer the one in my old case is too small a diameter and the 742 doesn't use a crush sleeve, I need a spacer right?, dose anyone know the part number for it so I can start searching? thanks.