Lapped the Main Drive Gear race for .0004 oversize rollers. This aftermarket (Motor Shop) case looks really good if anyone wants to know? The Jim's main race was already installed, but it was way out-of-round, the reason I had to lap it. Also installed new right side ball bearing. The counter shaft cluster gear is the "new style" fitted with needle bearings (instead of loose rollers and thrust washers) - They were removed, and new bearings pressed in very carefully to avoid crushing the bearing (and set them just below the surface of shaft). Proper end play was achieved with a thin thrust washer on counter shaft. I replaced main seal, cork, counter shaft o-ring . . . and a new main shaft snap ring. Hard part is over . . .