The race 320 extends and converges in width from {HEAD ~ the second end surface} 312 b to {TAIL ~ the vertical notch surface} 318 b 
The race 320 extends and converges in width from { HEAD ~ the second end surface } 312 b to { TAIL ~ the vertical notch surface } 318 b
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH