The 51HJ parts book lists three different bolts as part of the clutch pedal cross shaft...they are...
- Bolt (for the bushing) 5/16-24 x 3/4" round head cross recess (sounds like a big phillips head screw) - two required
- Oiler bolt 3/8-16 x 3/4" hex head (two required)
- Pivot jam nut 3/8-24 hex head (one required)