Got new 5.75 concentric coil today,the stock plastic bolt to mount coil,the mount hole is to small for stock bolt,well two choices,drill to bigger size,which i decided not to do because i felt it may break mount flange on coil,or choice #2 go to home depot,go to screw section,look in nylon bolt cabinet #10-24x1-1/2(2 in pack)get matching nuts(2 in pack)worked great.Chuck. cost=$1.24