One side of that material is V shaped to extend into and conform to the V shape of {HEAD ~ said race} sufficiently along {TAIL ~ the length} of the race for centering one plate 
sufficiently along
One side of that material is V shaped to extend into and conform to the V shape of { HEAD ~ said race } sufficiently along { TAIL ~ the length } of the race for centering one plate
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH