[Tigers] orientation of wedges between crossmember and frame

[Thomas Witt]

Yes, the thicker part at the rear is correct.  This induces a positive 
caster.  Some have even increased the Tigers caster by putting spacers on 
top of the thicker part of the wedge.

This increase in caster helps with directional stability, but typically 
increases the steering effort.  There is also a practical limit to just how 
much "wedge" one can put between the frame rail and the crossmember.  While 
effective, the wedge isn't a marvel of engineering.  At least with this 
setup an indexed, tapered washer would be appropriate on the crossmember 
bolt.
Tom