Below is the pertinent text from the document.
6.) Determine what thrust bearing to use on the CKP billet forward clutch drum (618) and machine Center Support (537) rear bushing journal to accept new thrust bearing thickness.
The roller thrust bearing is .010” thicker than the plastic washer and considerably wider. The Center Support would interfere with the roller bearing since it can no longer extend up thru it, so to accept the roller bearing the Center Support rear journal required machining to reduce it’s length, sinking it .020” below the Direct Drum. The rear journal was shortened by about 3/16” to accomplish this. The taper on the ID of the rear journal had to cut again. This may vary with each transmission and needs to be checked with modeling clay to verify there is a small amount of clearance between the rear journal and the TIG weld on the forward drum.
Plastic thrust washer thickness = 0.142”.
Roller thrust bearing thickness = 0.152”.
Roller thrust bearing OD = 2.157”.
Roller thrust bearing ID = 1.577”.
Center Support Journal OD = 1.745”.
Part #: 61493 OEM#: N/A
6a.) Machine forward clutch drum for needle bearing.
Buddy removed about .010” to make the surface flat everywhere. The surface starts at the TIG weld (ID) and continues across until you reach the raised surface (OD).