I built 2 408 with .002" rod and crank oil clearance and never had a failure with that at 7000rpm. Bearings had odd markings but never burned to copper on rebuilds. Street/strip deal. Local circle track engine builder builds all his sb chevys that way. I would never do that again thou. Always better to have .0025-.003" on rod and .003+ on mains. I have my 511 at .003 on rods and mains. I sleep better with it that way.