All axle builds for the rest of the season will have solid spacers installed for no extra charge on every rebuild of Ford 8.8's and 7.5's. Some people know that when applying high hp or a trans brake that the pinion nut will come loose when a stock crush sleeve is used. I have eliminated this issue with the use of a custom solid spacer and shims. I have these in stock ready for installation or you can purchase through me. PM me or call (586) 630-1098